Is it illegal for me to use a web extension to find out if my friend's list on Facebook changes? The specific example in question would be this site:


It notifies me any time someone's added to my friend's list or removed from it, and it tells me who's been added/removed. Is this legal? Thanks!

1 Answer 1


Using such an app doesn't seem illegal. There is no magic trickery or privacy violation involved with such apps, it just looks at your friend list:

  • Day 1: ask the FB servers for your current friend list and save it locally.
  • Day 2: ask the FB servers for your current friend list again and compare this list with the saved list from day 1.
  • Notify you about differences in the friend list.

This does not give you any information you didn't already have access to.

However. The app or extension needs to access Facebook with your permissions to access this information. There are ways to do this securely, so that you only grant the app access to your friend list. A browser extension is not such a way. A browser extension can bypass any security protections Facebook has implemented and can see everything you can see.

So you should only use such apps if you totally trust the app developer. There's a lot of shady software that preys on people's anxieties: who unfriended me? who is currently looking at my profile? Not all such extensions are created to your benefit. Remember the Cambridge Analytica scandal? Some people claimed that they had access to internal Facebook data. Not so. They provided extensions and applications that end users happily installed. Users granted these applications access to their Facebook data. Maybe they didn't read the privacy policy, maybe the privacy policy wasn't even truthful. But the result was that an unethical actor used “legal” means to violate the privacy of lots of people.

So while using this app might not be illegal, you should think carefully before installing it – maybe the app is doing something illegal with your access.

  • Thanks for the info! What did you mean when you said, "A browser extension is not such a way." Do you mean that browser extensions don't ask permission, or do you mean something else?
    – The Editor
    Jul 20, 2021 at 13:44
  • @TheEditor When you access Facebook through a web browser, the browser sees everything you see (and possibly much more). Extensions like the one you linked are part of the browser, so it also has unfettered access to Facebook in your name. This bypasses Facebook's normal security checks for third party applications. If you're interested in the theoretical security background of such issues: this is a so-called confused deputy problem.
    – amon
    Jul 20, 2021 at 15:57
  • Okay, so there's nothing illegal. So as long as I trust the site not to take advantage of my info, I should be fine. Thanks!
    – The Editor
    Jul 20, 2021 at 19:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.