A new Facebook application that could be used by advertisers to target users based on their personal preferences and those of their friends is raising privacy concerns in Canada, experts say.

The application, announced last Wednesday, allows Facebook users to publicly connect with other websites they like and share them with their friends.

When users click a button called “like” on any one of the 70 participating websites, a link to that page is added to their Facebook profile.

In addition, Facebook has linked up with three sites, including Microsoft Corp.’s doc.com, Pandora, and Yelp! where users’ Facebook content is used to personalize the content and connect them with their friends.

“It’s what I and others call ‘soft surveillance,’” said Ian Kerr, a University of Ottawa law professor and Canada Research Chair in Ethics, Law & Technology.

“Marketers are building their social graphs based on their social networks, mapping connections between people.”

It’s taking online tracking and profiling to a whole new level, Kerr warned, comparing it to Google Streetview for social networks.

“So if some of your friends are deadbeats, marketers may conclude you are a bad risk, too,” Jules Polonetsky, director of the U.S. based Future of Privacy Forum added.

Facebook users can opt out of this feature, Kerr said.

But few online users exercise privacy options despite their concerns about the potential for abuse, the conference hosted by Canada’s Office of the Privacy Commissioner heard.

The office is monitoring Facebook’s activities closely, assistant privacy commissioner Elizabeth Denham said in an interview.