BuzzFeed News – “…Facebook collects information about its users in two ways: first, through the information you input into its website and apps, and second, by tracking which websites you visit while you’re not on Facebook. That’s why, after you visit a clothing retailer’s website, you’ll likely see an ad for it in your Facebook News Feed or Instagram feed. Basically, Facebook monitors where you go, all across the internet, and uses your digital footprints to target you with ads. But Facebook users have never been able to view this external data Facebook collected about them, until now. Facebook tracks your browsing history via the “Login with Facebook” button, the “like” button, Facebook comments, and little bits of invisible code, called the Facebook pixel, embedded on other sites (including BuzzFeed News). Today the company will start to roll out a feature called “Off-Facebook Activity” that allows people to manage that external browsing data — finally delivering on a promise it made over a year ago when CEO Mark Zuckerberg announced at a company event that it would develop a feature then called “Clear History.”
The new tool will display a summary of those third-party websites that shared your visit with Facebook, and will allow you to disconnect that browsing history from your Facebook account. You can also opt out of future off-Facebook activity tracking, or selectively stop certain websites from sending your browsing activity to Facebook. Nearly a third of all websites include a Facebook tracker, according to several studies. Some people in Ireland, South Korea, and Spain will gain access to Off-Facebook Activity first. Facebook said it will continue rolling out the feature everywhere else over the coming months. The tool, found in account Settings > Off-Facebook Activity, includes an option allowing you to “clear” your browsing history…”
See also the related Facebook Newsroom blog posting.