You may have thought you deleted that embarrassing Facebook photo of you spilling a big-gulp beer at your uncle's barbecue. But it may still live online. Despite recent steps to allay the fears of privacy advocates, Facebook is "is still struggling when it comes to deleting user photos—or not deleting them, as the case may be," according to the tech blog Ars Technica. That site found that 16 months after deleting a Facebook photo, the offending image was still available in the recesses of the internet. Do Facebook photos ever go away? Here's a brief guide:

Can anyone still see a deleted picture?
When you erase an image from Facebook, it ceases to show up among your profile photos right away. But "a direct image link" — that is, a web address that directs the user to a cached version on Facebook's servers — "will still provide access to a deleted photo." In other words, since Facebook has not fully deleted the photo from its database, it's still online for anyone who has the URL for it.

How was the problem discovered?
Ars Technica had written about the photo deletion problem in 2009 when Jacqui Cheng discovered that an embarrassing photo that she had deleted from her profile was still accessible with the direct URL. At the time, Facebook assured her that it would "significantly reduce the amount of time that backup copies persist"— but when Cheng checked back on the problem last week, the original photo was still there. Since Cheng's discovery, other readers have come forward with similar stories.

Is Facebook doing anything about this?
A spokesman said that the photo was almost inaccessible, comparing its deletion to "what happens when you delete information from the hard drive of your computer." The problem, says Ryan Tate at Gawker, is that "your hard drive is not indexed by search engines like Google, cached in web browsers or as easily scraped and archived for posterity by web hackers." On the heels of negative publicity, Facebook expunged Cheng's photo and now claims it's working on "a fix that will delete photo and video content from the CDN's cache shortly after it's removed on Facebook." Nonetheless, says Amar Toor at Switched , "it's probably a good idea to refrain from uploading any embarrassing photos in the first place."

Sources: Ars Technica, Switched, Gawker