caption: Carnegie Mellon's Alessandro Acquisti shows how to use Facebook to ID people on dating sites and on the street

(Credit: Declan McCullagh/CNET) LAS VEGAS--Facebook's online privacy woes are well-known. But here's an offline one: its massive database of profile photos can be used to identify you as you're walking down the street. A Carnegie Mellon University researcher today described how he assembled a database of about 25,000 photographs taken from students' Facebook profiles. Then he set up a desk in one of the campus buildings and asked willing volunteers to peer into Webcams. The results: facial recognition software put a name to the face of 31 percent of the students after, on average, less than three seconds of rapid-fire comparisons. In a few years, "facial visual searches may become as common as today's text-based searches," says Alessandro Acquisti, who presented his

Google+ vs. Facebook: 6 Things Google+ Has That Facebook Doesn't

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Google is gunning for Facebook. The search giant recently launched Google+, a social networking site that aims to rectify the company's failed social media efforts, such as Google Buzz and Wave, and put a dent in Facebook's business. So does Google+ stand a chance against Facebook, which is now over 750 million users strong and has been valued at $100 billion? Google isn't giving up without a fight: the behemoth needs a hit in the social space and one Google executive called Google+ a bet-the-company effort. To help you decide, here's a look at six features Google+ has that Facebook doesn't (You can see what they have in common here).

1. Hangouts: Video Chat With A Group

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One key element distinguishing Google+ from Facebook is a feature called "Hangouts" that offers users a way to join group video chats. Picture a chat room, but with video: Any user can create a Hangout, which

Google +1 button Explained: What Happens When You Click It?

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Google has made its latest foray into social media with the launch of its +1 button, a tool that the search giant hopes will accomplish two feats: make Google a legitimate player in the social space while helping return more relevant search results to its users. What is Google +1? Google's promotional video for the +1 button explains the social feature thus: "When you click +1, you're telling your friends, your family and the rest of the world, 'this is something you should check out!'" In that sense, the Google +1 button is similar to Facebook's "Like" button. But instead of your "Likes" -- or in this case, your +1's -- being posted to your Facebook profile, your +1's are collected in your Google profile and displayed when people within your Google social circle search for something you've recommended. How to use Google +1: If you've opted in via Google Labs, you'll