[fjsolwmv]

If you log into Facebook on web, then visit any other site, they send your browsing info to Facebook via Like button.

The Facebook app is more sandboxed, since it can't snoop on your web browsing.

[mkl]

The Facebook app can and does track your physical location, among other things.

I think the real answer is "Don't use Facebook" or "If you must use Facebook, do it through Tor Browser".

[michaelmrose]

The facebook app for quite a while was actually sending facebook data about your phone calls and sms so guess again.

[scarface74]

Only on Android....they couldn't do that on iOS.

[viraptor]

The like button can't track you if you block it ;-)

[Casseres]

I use a seperate web browser on my phone for Firefox and Gmail. Everything else, I use Firefox.