Facebook Apps Leaking User IDs Including FarmVille

According to a Wall Street Journal article Facebook’s top 10 applications have been leaking data that can be used to identify users to advertising and Internet-tracking firms. That’s in violation of the popular social network’s own privacy policies and has raised doubts about Facebook’s ability to protect confidential information concerning its users’ online activities and preferences. An investigation conducted by the Wall Street Journal claims that millions of Facebook app users have already had their Facebook ID numbers passed on to third-party advertising and tracking companies.

The content of a Facebook application like FarmVille is loaded within an iframe on the Facebook page. The content loaded by farmville.com in the iframe contains the game alongside third party advertisements. When your browser goes to fetch the advertisement, it automatically forwards to the third party advertiser referer information The URL of the current page that’s loading the ads. for FarmVille. URLs to include the user’s Facebook ID, the browser will forward this identifying information on to third parties.

Facebook says they have disabled thousands of apps since the issue came to light. The company says that the current problem is more challenging.