Social actions are powerful because they act as trusted referrals and reinforce the fact that people influence people. It’s no longer just about messages that are broadcasted out by companies, but increasingly about information that is shared between friends. So we set out to use these social actions to build a new kind of ad system.”

–Facebook CEO Mark Zuckerberg

“Once every hundred years media changes.” With that vainglorious pronouncement, Zuckerberg on Tuesday ushered in a new era of socially networked advertising.

Or did he? Because according to Daniel J. Solove, an associate professor of law at the George Washington University Law School, combining a Facebook user’s name and image with an advertiser’s message in a so-called “Social Ad” without that user’s express permission may be illegal.

“It seems as though Facebook might be assuming that if a person talks about a product, then he or she consents to being used in an advertisement for it,” Solove writes. “But such an assumption might be wrong, and the use of a person’s name or image in an advertisement without that person’s consent might constitute a violation of the appropriation of name or likeness tort. … According to the Restatement (Second) of Torts § 652C: ‘One who appropriates to his own use or benefit the name or likeness of another is subject to liability to the other for invasion of his privacy.’ “

Now Facebook claims no personally identifiable information is shared with an advertiser in creating a Social Ad. “Facebook has always empowered users to make choices about sharing their data, and with Facebook Ads we are extending that to marketing messages that appear on the site,” the company explains. “Facebook users will only see Social Ads to the extent their friends are sharing information with them.” That’s certainly a thoughtful assurance. But it doesn’t exactly address the issue of Facebook appropriating user identities for its own benefit.