Facebook users may be convinced that they "own" whatever content they post to Facebook, but the legal reality is a little bit different.
If you read Facebook's legal terms of service, you'll find that "[y]ou own all of the content and information you post on Facebook," but with some very specific and important caveats.
So what does it mean to legally "own" your Facebook posts?
Your Words and Information
That means if you share your recipe on Facebook, and celebrity chef Bobby Flay decides to appropriate it for his next cookbook, you won't be getting any royalties. This is partially because recipes generally aren't available for copyright, but most of your posts containing words and information aren't either.
Your Photos and Videos
Facebook users have slightly more rights to the photos and videos which you post to the site, as those works are easier to protect via copyright. However, Facebook's terms allow them "a non-exclusive, transferable, sub-licensable, royalty-free, worldwide license to use any IP content that you post on or in connection with Facebook." In layman's terms, Facebook has license to use the photos and videos you post (which you own) in any way it sees fit, without paying you, and it can transfer that license to third parties.
Typically, you could sue a company like Facebook for using your image without your permission (or without paying you) under your rights of publicity. But by joining Facebook, you've essentially given the company carte blanche to do what it will with your images and videos, not to mention whomever Facebook decides to share your media with.
Can You Revoke Facebook's License?
Kinda. The control over your photos, videos, and even information may only last as long as content is active on Facebook. Once it's deleted, Facebook's terms state that its incredibly expansive license ends...
That is, unless you've shared your content with friends. Facebook's IP license doesn't officially terminate if "your content has been shared with others, and they have not deleted it."
So users beware: You may "own" what you post to Facebook, but your rights to stop others from using it are very limited.