Facebook has drawn the ire of thousands of its users, and has once again bowed to the pressure of the political campaign against its advertising techniques. Facebook has made significant changes to its recently launched Beacon advertising platform after 50,000 Facebook members signed a MoveOn.org petition over a 10-day period, asking the site to respect user privacy.

Beacon sends messages to members friends about what they are purchasing online. If the member booked a trip to Japan on Travelocity.com, for example, friends on Facebook would know it. If the member purchased a ticket to “American Gangster,” that would also be known among friends.

Facebook backpedaled. The social-networking site now says it won’t send messages about members’ Internet activities without getting approval each and every time. Members will opt in to the program.

Big Brother Is Watching

When Facebook launched the program on November 6, it wasn’t positioned as a Big Brother scenario. The new advertising solution was positioned as an option to share actions on other sites with friends on Facebook.

“Just as Facebook shares your on-site interactions with your friends through News Feed, we now give you an option to let News Feed share your off-site actions with your friends as well,” explained Leah Pearlman, the product manager for Facebook ads, in the company blog.

She figured adding the first season of Buffy the Vampire Slayer to your queue on Blockbuster.com might be something you want your friends to know about. Pearlman also promised members complete control over the information. The only problem, as far as privacy advocates were concerned, is that members had to opt out instead of opting in.

MoveOn.org launched its petition on November 20, saying Beacon was an invasion of privacy. The petition reads, “Site like Facebook must respect my privacy. They should not tell my friends what I buy on…