Chicago: Even the privacy-conscious people freely hand over personal information to perfect strangers on social networking sites. They do so every time they download and install what's known as an "application," one of thousands of mini-programs on a growing number of social networking sites that are designed by third-party developers for anything from games and sports teams to trivia quizzes and virtual gifts.

On some sites applications can only be downloaded if a user checks a box allowing its developers to "know who I am and access my information," which means everything on a profile, except contact info. Given little thought, agreeing to the terms has become a matter of routine for the nearly 70 million Facebook users worldwide who use applications to spruce up their pages and to flirt, play and bond with friends online.

So what do these third-parties do with the information? Sometimes, they use it to connect users with similar interests. Sometimes, they use it to target ads, based on demographics such as gender and age (something Facebook and MySpace also do).

Experts who track online security issues think there's too much personal information flying around out there, with few guarantees that it's safe. They also think social networkers have little understanding where their information goes and how it's used — and as a result, have a false sense of security.

"I suspect that there's a whole lot of clicking without a lot of thinking," says Mary Madden, a senior research specialist at the Pew Internet & American Life Project who studies privacy issues. "So much of this sharing happens in a way that users don't see the consequences. It's kind of a big, black hole."

Jayant Agarwalla, co-founder of Facebook's popular Scrabulous application, a takeoff on the game Scrabble, says Scrabulous does use demographic information to target ads that show up as a person plays the game. But Agarwalla stresses that that information is provided in "real time" and not stored. "In my humble opinion, users have nothing to worry about," he adds.

Whether the profile is private or not, users should limit the information they post, said Tom Jagatic, one of the researchers and now a senior information technology consultant at the Massachusetts Institute of Technology.

It's good advice, says Jeremy Miller, a fraud investigator based in Nashville, but he wonders how many will heed it. "It's kind of a status symbol, so privacy takes a back seat," says Miller.

Also read:

Beware of hacker attacks via networking sites

Ten ways to be safe on Social networking sites

Source: Associated Press