• by Wendy Davis , Staff Writer @wendyndavis, November 9, 2007

There's been a lot of talk this week about whether Facebook's new ad plan -- which involves enlisting members as brand evangelists -- is a stroke of brilliance, massive invasion of users' privacy, or both.

Now, real questions have surfaced about whether the program is even legal.

Facebook's new plan involves serving members ads that include the names and photos of members' friends who have signed up as fans of the advertisers.

The problem, according to University of Minnesota Law School professor William McGeveran, is that a 104-year-old New York law prohibits advertisers from using photos, drawings or other likenesses of people without their written permission. Courts in other states as well have held that people can sue when photos or drawings of them are used in ads without their consent.

Facebook's chief privacy officer Chris Kelly tellsThe New York Times that members have no cause to complain because they chose to publicly become a fan of the advertiser.

Ultimately, courts might well agree with Kelly on this point. But that doesn't mean that some disgruntled users won't sue. Even if most Facebook members decide they like the program, or are at least indifferent to it, surely some will be unhappy enough to mount a legal challenge. And it now appears that they might have the ammunition they need to file a case, even if they don't ultimately prevail.