In its latest salvo in the fight against spam, Facebook has filed a patent application for a “social CAPTCHA” system.
CAPTCHAs, which ask people to re-enter a code displayed visually, have become well known as the main system for blocking spammers on the web. Facebook believes the social CAPTCHA will prevent spam even more effectively. The picture, right, is of Facebook’s current CAPTCHA system, not of a social CAPTCHA.
Social CAPTCHAs ask individuals questions they should know the answers to – such as identifying who a peson in a picture is. If they can, they have effectively validated their identity. You can read the details of the patent application here.
This isn’t exactly new as Facebook has been testing the system for months, however Facebook is now attempting to patent the system. Interestingly enough, Google happens to be the owner of the most popular text-based CAPTCHA system, reCAPTCHA.
The idea is that if hackers obtain access to a Facebook user’s account, they would be unable to answer the questions posed by the social CAPTCHA.
Go Rumors points out that this would not help if the person who is fraudulently accessing the account is in the same network of friends as they would then know the answers. This is true but I don’t think this is a problem for a couple of reasons. Firstly, I would guess that the vast majority of compromised accounts are hacked by a third party, unknown to the user. Secondly, it’s still an improvement on an ordinary CAPTCHA, since ordinary CAPTCHAs only protect against bots and can be theoretically answered by any human.
Personally I might find a social CAPTCHA easier to use, simply because I have trouble with ordinary CAPTCHAs. The numbers and letters often look ambiguous to me and I find I frequently have to make several attempts before I answer it correctly. I’m much better at recognizing my friends faces – as long as their profile pics are actually of them and not their baby or pet dog. However, I would guess social CAPTCHAs might make life difficult for some people, especially those that like to friend a lot of people that they don’t actually know and also anyone with visual impairment.
In fact, this photo (via ReadWriteWeb) is a perfect example of what can go wrong with a social CAPTCHA. It was provided by author Eleanor Herman who is Facebook friends with a lot of her readers. Even if she did recognize all of her readers, I can’t imagine that any of them actually look like gummi bears!