Facebook has built a highly popular business, but it turns out making that popularity profitable appears to depend, in large measure, on advertising. Sound familiar? So Facebook announced a new program, Beacon, an online tracking tool. No, online tracking certainly isn’t new: companies track where your browser has been and your online activity, and routinely serve up ads based on “preferences”—where you have been, what you look for, and what you purchase. But that takes place behind the scenes—you just see the results: relevant, targeted advertising.

Facebook has taken online tracking one step farther: Beacon sends messages telling your Facebook buddies what you are buying and, in some cases, what you are doing. So don’t plan that surprise trip to Puerto Rico just yet—buying a ticket might ruin the surprise. In fact, don’t come back from the trip and rate the hotel—your friends who weren’t invited will know you’ve been there.

Facebook faced criticism last year when its “News Feed” function came under fire. Media and industry pundits and Facebook executives note often schizophrenic and hypocritical marketplace attitudes. Indeed, there is some irony to be considered when the generation that posts profiles, adding everything from drinking, sexual preferences, and religious affiliations, to family videos, in blatantly public web-spaces, complains about privacy. But consumers still distinguish between their choice to share, and allowing a host to decide what, when, where and how to share information about them, or whether to characterize activities as some form of an “endorsement without consent” to their friends.

As usual, privacy and consumer advocacy groups were poised to file complaints with the FTC, right on the heels of investigations already launched by several Attorneys General into Facebook’s privacy practices. The New York Attorney General has issued a subpoena to Facebook for copies of complaints about “inappropriate solicitation of underage users and inappropriate content on the site.” As innovators have learned, success shines a spotlight that creates a glow—and discloses warts; let’s see if they can keep Facebook blemish-free.