From friend lists to finding the truth.
With nearly 3 billion monthly active users, Facebook remains the world’s third most popular website and one of the richest data sources available – even if its average userbase has gone up twenty years in age in half as many years. The average person spends just under 35 minutes on Facebook a day, so if you’re investigating individuals, mapping networks, or tracking digital footprints, Facebook is a powerhouse for OSINT work. From status updates to profile details, group interactions to public posts, Facebook is a treasure trove.
In this guide, we’ll dive into the latest OSINT techniques to help investigators ethically and legally extract valuable intelligence from Facebook. Let’s log on to Facebook OSINT to connect Facebook profiles with phone numbers, uncover Facebook email addresses and employ professional-grade methods to enhance OSINT investigations on Meta’s groundbreaking platform.
What are OSINT and SOCMINT?
If you’re already an OSINT professional, this is your signal to skip ahead to the next section.
For those new to the field, Open-Source INTelligence (OSINT) means collecting and analyzing publicly available data. This data comes from anywhere public: news websites, government databases, business registries and social media platforms like Facebook, X (Twitter), and Instagram. Anywhere that’s freely accessible, without restriction.
Everyone from cybersecurity professionals to journalists, law enforcement, and private investigators uses OSINT to track online activity, verify identities, uncover hidden networks, and analyze behavior. For more uses, check out ‘OSINT Basics: What is OSINT?’.
The key aspect of OSINT (that distinguishes it from all other types of intelligence) is that all information is collected via open sources – no hacking or unauthorized access involved.
A subcategory or branch of OSINT, Social Media INTelligence (SOCMINT), specifically focuses on extracting intelligence from social media platforms like Facebook. Given its vast user base and the amount of data people willingly share, Facebook is not only a prime OSINT resource, it’s a prime SOCMINT resource.
Status Update: How Does Facebook Work?
Did a group of college roommates know what they were setting into motion when they created ‘TheFacebook’? Did Mark Zuckerberg, Eduardo Saverin, Andrew McCollum, Dustin Moskovitz, and Chris Hughes wake up on February 4th 2004 planning to eventually mount one of history’s largest tech IPOs? Probably not.
Still – from a social networking platform initially exclusive to Harvard University students, Facebook has come a long way to reach the smartphone or desktop of just about anyone aged 13 and older with a valid email address. Over the years, Facebook has added the News Feed, the "Like" button, and Facebook Messenger; even if you can’t remember the less successful ventures (Facebook Gifts, anyone?) you can probably remember when we could Poke each other.
Instagram, WhatsApp and Facebook are now grouped together Meta, to suggest building the ‘metaverse’ with virtual reality and augmented reality (AR) technologies. It’s unlikely we’ll all be running around as legless avatars in Horizon Worlds, but Facebook remains one of the most influential platforms in the world – or at least the most popular.
Before launching an investigation, it’s crucial to understand which features make Facebook unique from other platforms. It might feel like a recap for anybody who’s been online in the 21st century, but this is an important first step. From understanding the inner workings of Facebook we can better understand how its features can be leveraged for OSINT.
Privacy Controls & Public Data
Unlike international platforms like VK where it's normal for users to openly share details, Facebook has a culture of stricter privacy controls. Regardless, many users still leave personal details publicly accessible – or just have bad OpSec – leaving Facebook still packed with OSINT when approached strategically.
Profiles & Connections
Even with privacy settings set high, valuable information can often be extracted from:
- Profile pictures & cover photos
- Work and education details
- Friends lists (if public)
- Groups and liked pages
- Tagged photos & location check-ins (GeoINT)
Facebook Groups & Community Interactions
We all join at least one meme group. Facebook groups are an incredibly rich source of OSINT. Many investigations start by identifying a user’s interests, political views, professional affiliations, personal connections or even sports team support through group memberships. In fact, they’ve become a keystone of background checking for colleges and employers.
Meta Commentary: Why OSINT on Facebook?
If having 3.07 billion monthly active users (MAUs) isn’t persuasive enough, Facebook, as the most used social media platform on the web, is one of the most valuable platforms for SOCMINT for three reasons: a colossal user base, a focus on detailed personal data, and a ready-made map of social interactions.
As users are encouraged to interact with content and express opinions, investigators can extract intelligence from public posts, profile information, comments and reactions to gauge sentiments and affiliations on practically any topic. As we’ve discussed, groups and pages often expose ideological leanings too, and event participation and organizational ties can be crucial for tracking persons of interest across the globe. With most of its MAUs as far afield as India and Indonesia, Facebook also doesn’t fall into the same trap as socials like Discord that are overwhelmed by American and English-speaking users.
Facebook means more OSINT, and more international OSINT. Even when profiles are private, investigators can often access friend lists, tagged photos, and check-ins and more networks and locations. That’s without mentioning advanced techniques like analyzing engagement patterns or leveraging Graph Search. Even for critical OSINT tasks like threat analysis, fraud investigations (more on that later), or digital forensics, Facebook is inarguably an essential OSINT resource.
Facebook OSINT: Three Key Approaches
Here are the latest OSINT techniques for extracting intelligence from Facebook, divided into three core areas: Facebook user details, Facebook phone numbers and Facebook email addresses.
Find Facebook User Details with OSINT
Facebook profiles often contain valuable identifying information. You might be using a name or username you already have to find further details, or searching for a Facebook account with a certain name or username that you don’t yet have. Here’s how to do both:
To find a Facebook user, you can try:
Search Engine Dorking
Google Dorking can help uncover public Facebook profiles and posts therein. You can try dorks like:
site:facebook.com "[username]"
site:facebook.com "[email]"
site:facebook.com "[John Doe]" "New York"
Facebook Search & Advanced Filters
Facebook’s own search engine is relatively powerful. Try searching for a name and location, or filtering by ‘People,’ ‘Photos,’ ‘Posts,’ or ‘Groups’ depending on what you’re looking for.
Investigating Mutual Friends & Tagged Photos
Even if a target profile is private, mutual friends or tagged photos might not be. If they’re visible, that can reveal leads via mentions or presences on friends lists.
To find details from Facebook user, you can try:
Checking Public Profiles
A great thing about Facebook profiles is that bios, workplace, location, relationship status, and profile picture metadata are usually public. Even restricted profiles have cover photos, featured images, or username patterns. Take a look at a profile first, and see what you can see without any major effort.
Graph Search Alternatives
May Facebook's official Graph Search rest in peace! While the official version of this invaluable tool is gone, certain URL parameters can still retrieve posts, photos, or tagged content like the old days. Try:
“facebook.com/search/str/[query]/keywords_users”
Monitoring Facebook Marketplace
As covered more intensively below, listed items for sale on Marketplace can be tell-alls. On Marketplace, a user’s past listings stay visible alongside current listings – both can yield juicy location data for GeoINT, and more tasty morsels of intel.
Check-Ins
Another pro GeoINT source, check-ins and reviews at businesses or events can reveal movement patterns and frequently visited places. This is similar to what’s revealed by searching on OSINT tools like OSINT Industries, which can tap into Google reviews as well as Facebook ones.
OSINT Tools like OSINT Industries
As the previous entry suggests, a Facebook username search with OSINT Industries can reveal vast swathes of additional data. Using a Facebook username as a selector for a search across 1000+ OSINT sources, our tool aggregates everything into comprehensive and easy-to-read results. You can see your findings as a timeline or map, or go further with OSINT Industries Palette.
Find Facebook Phone Numbers with OSINT
Their usefulness as search selectors, and localized area codes, make phone numbers vital OSINT finds. Some Facebook users share phone numbers – most commonly in professional settings like business pages. However, it’s uncommon for users to just publicly post their phone numbers on their Timeline, for everybody to see, on the largest social platform in the world. Most people don’t want to be deluged with phone calls, and this means some OSINT work is normally required. If your subject is the type with reasonable OpSec (and common sense), here’s how to dig out those digits:
To find a phone number from a Facebook account, you can try:
Phone Number Lookup
Many OSINT tools, such as OSINT Industries and Maltego can help you out with lookups to find linked Facebook profiles. Try reverse email lookups or reverse username lookups, leveraging the data you’ve got to get the data you haven’t. Just flip it and reverse it.
Facebook Marketplace & Ads
Again, contact details are a must when selling products or services on Marketplace. The result? Searching Marketplace can often reveal a Facebook phone number. Business pages or local area groups can also perform the same function, with some GeoINT data for seasoning. Access Marketplace with the techniques listed below.
Dorking for Phone Numbers
If looking in all the logical places doesn’t yield results fast, turn to Google Dorking. Look for phrases that suggest a reasonable context for sharing a phone number, like ‘contact’ or ‘call’. The following dorks are ideal for locating Facebook phone numbers with a search engine:
site:facebook.com “[phone number with area code]”
site:facebook.com “contact me”
Find Facebook Email Addresses with OSINT
The value of email addresses in OSINT investigations cannot be overstated. Email addresses are unique identifiers, often login credentials, and are perfect search selectors for OSINT tools. Like phone numbers, most Facebook users don’t openly display their email addresses on their profiles. Most people prefer to keep their inboxes spam-free, but good investigative techniques can comb Facebook’s features for that all-important email intel. Here’s a few OSINT methods to track down a Facebook email address:
To find an email address from a Facebook account, you can try:
‘About’ Sections & Business Pages
If you’re looking for Facebook email intel on a business minded subject, you’re in luck. Some users list their emails openly in ‘About’ sections – especially professionals or business owners.
Checking Group Posts & Discussions
Another technique that works best with business owners, or those who use Facebook for business; considering 93% of businesses have a Facebook presence, that’s more people than you’d think. Users often post emails in group discussions for networking or recruitment purposes.
Using OSINT Tools for Reverse Email Lookups
Reverse lookups can find the data you’re looking for. Conduct a reverse email or reverse phone lookup on a platform like OSINT Industries, and analyze the accounts revealed. Has your Facebook user publicized their email address on another platform? Is the email presented in your results?
What About OSINT on Facebook Marketplace?
As you may have noticed, Facebook Marketplace is a valuable resource for OSINT investigations – perhaps the most valuable feature on Facebook.
Facebook Marketplace is an eCommerce platform integrated into Facebook, that allows users to buy and sell on the social platform. Buying and selling requires more openness about concrete personal details from users, who can freely post phone numbers and emails.
When you look at a Marketplace profile, you can access both current and past listings. Analysis of these can expose a lot of intelligence for your investigation. Namely – behavioral patterns, financial insights, approximate locations (GeoINT) and more.
While conducting OSINT on Facebook Marketplace, look out for:
User Information
- Full or Partial name (often included in listing, e.g. “Ask for [first name]…”)
- Profile picture (hopefully, real)
- Profile link (direct access to Facebook account)
- Other listings (pattern analysis of sales and purchases)
- Joining date/Account creation date (for estimating account age)
- Location (based on location settings, local activity or listing details)
Listing Details
- Item names & descriptions (seller intent, origin of items or reason for sale)
- Price history (if price is adjusted over time, can suggest finances)
- Photo Metadata (may include location or device info)
- Condition of items (gives insight into seller's habits or finances)
- Category & tags (trends in selling and buying behavior)
Location & Behavioral Data
- Seller's location (based on listing map, settings or named location – vital for GeoINT)
- Frequent selling areas and habits (if multiple listings are there)
- Travel patterns (can trace movements, if listings appear in different cities)
- Seller’s home or workplace (if sales are frequent in one spot on the map)
Communication & Facebook OSINT
- Seller's response time (indicates an active or inactive user – and how often the subject uses Facebook)
- Preferred contact method (access to Messenger and phone or email if shared)
- Language & writing style (useful for pattern recognition and profiling)
- Negotiation patterns (common pricing behavior)
Technical & Hidden Data
- Image metadata (EXIF) (if not stripped by Facebook)
- Unique listing ID & URLs (can be used for tracking hidden and deleted posts)
- Facebook Pixel tracking (a more advanced technique – if visiting from a logged-in session)
Not only SOCMINT, but eCommerce-focussed OSINT methodologies come into play on Marketplace. Of particular interest are three details – which items your subject is selling, their approximate location, and the activity pattern of a Facebook Marketplace account.
Analyze the types of items a user frequently lists. From these, you can infer hobbies, interests, part-time businesses or ‘side hustles’, and even signs of financial distress – or success. This is helpful for law enforcement. Repeated sales of high-value items suggest a need for quick cash, or even stolen goods. Frequent postings in multiple locations could suggest erratic travel, or even potential fraud.
Keep an eye on account activity. Watch the communication aspect of Marketplace — like how a user responds to inquiries, or the language used in listings. You can get clues about a Facebook user’s background and engagement style from the way they message or post. Account creation dates, for example, can suggest a subject’s age. Reviews can suggest trustworthiness. Users might also divulge information like emails or phone numbers while chatting.
Look for location data in listings; Marketplace is the best way to find out where a user is. Trace connections between buyers and sellers too. If a user interacts with the same people across multiple transactions, these might be local users or have close social or business links to your subject. Marketplace reviews, if available, can also give away GeoINT.
To view a user's Marketplace profile, find out their Facebook User ID (username) and incorporate it into this URL:
“https://www.facebook.com/marketplace/profile/[USERID]”
Inputting this URL will allow you to explore all their listings, and open up all the intel you can gather from analyzing them.
Legal & Ethical Considerations in Facebook OSINT
Facebook OSINT is powerful, if it’s conducted ethically. To stay on the right side of the rules, always:
- Use exclusively publicly available, open-source information
- Respect privacy laws (e.g., GDPR, CCPA)
- Never hack, phish, or seek unauthorized access (not even once)
Some say Facebook has peaked, but Meta’s first platform remains a critical source for OSINT investigations. With the right techniques — leveraging search engine dorks, mastering Facebook’s internal search, deploying OSINT tools, and analyzing public user data — Facebook can uncover valuable intelligence legally, ethically and fast.
To see Facebook OSINT in action, check out our Case Study.
“OSINT_Tactical’s addition to our platform gave our users open access to the hustle and chaos of Facebook Marketplace…”
Read: Using Facebook to Crack Fraud and Find Missing Persons with OSINT Tactical
