Sheryl can't be happy about these pesky lawyers Crossroads Foundation Photos Update: Facebook says, "We believe this suit is completely without merit and we will fight it vigorously."

Earlier: Just as Facebook COO Sheryl Sandberg seems to have finally figured out social media advertising, Facebook's booming business is under a new legal threat.

A big reason Facebook's revenues will approach $2 billion this year is that when you click "like" on a Facebook ad, Facebook will sometimes tell your friends in a new ad. When people see Facebook ads featuring someone they know, they are 300% more likely to remember the brand featured in the ad.

This is Facebook's secret sauce.

But suddenly, it's under threat. A group of lawyers in California say that when minors click on Facebook ads and Facebook turns around and uses these minors' names and photos in later ads, Facebook is breaking a California law which requires parental consent for using a minor's name in an ad.

These lawyers say Facebook is “misappropriating the names and pictures of minors for profit" – so they're suing.

Here's the class-action suit:

Complaint (as Filed) - Cohen v Facebook Inc