F.B. Purity is a browser extension that, in its author's words, "helps you to take control of the News Feeds on your Facebook home page. It does this by filtering out the application spam, such as quizzes and games etc, and also the messages such as 'x became a fan of y'". It also allows you to fix FB's broken "Timeline" layout. I don't use it myself -- I use a combination of other browser tools to filter Facebook -- but I have friends that swear by it.
The author of this software reports that he's now been banned from Facebook:
Facebooks legal department have informed me, the developer of the F.B. Purity browser extension, that I am *banned* from using Facebook. This effectively means I will no longer be able to work on the F.B. Purity project any more. I am assuming the F.B. Purity fan page will also be shutdown when they commence the ban. They have not said when the ban will start, but it could happen at any time.
They say the reasons for the ban are:
“Facebook’s terms specifically prohibit interference with the way Facebook is rendered to its users” and that the extension doesnt connect via their “API”, which they say is the approved method for interacting with Facebook’s services.
F.B. Purity does not directly access facebook’s services anyway, it is a browser extension, and by definition, it “extends” the browsers functionality, therefore it is actually the web browser itself that is accessing Facebook, and web browsers do not need an API key or license to access Facebook’s services, as Facebook is designed to run in a web browser.
Hey, Facebook: the more you tighten your grip, the more users will slip through your fingers. You have no legal authority to prevent people from writing or installing browser extensions -- any attempt to require this by a contract of adhesion is clearly unconscionable. You can ban whoever you like, but banning extension authors is a P.R. disaster.