Tens of millions of Facebook users, who use some of the service’s most popular applications, may be subject to a privacy breach that reveals personal information to advertisers.
According to a Wall Street Journal investigation, all of the 10 most popular apps on Facebook, including games such as FarmVille, share user information with outside agencies that aggregate consumer information in order to better target advertising messages.
This practice, write Emily Steel and Geoffrey Fowler, is an apparent violation of Facebook’s privacy policies:
“The information being transmitted is one of Facebook’s basic building blocks: the unique ‘Facebook ID’ number assigned to every user on the site. Since a Facebook user ID is a public part of any Facebook profile, anyone can use an ID number to look up a person’s name, using a standard Web browser, even if that person has set all of his or her Facebook information to be private. For other users, the Facebook ID reveals information they have set to share with ‘everyone,’ including age, residence, occupation and photos.”