Associated Press/ Chris Pizzello

Prince has done it again, suing 22 internet users for $1 million each for "massive infringement and bootlegging" by posting his copyrighted material -- including footage of concerts dating back to the 1980s -- on their Facebook pages or websites.

The lawsuit, filed in U.S. District Court in San Francisco, lists only two defendants by name. The rest are John Does.

It's the latest in a long line of legal actions that Prince has taken to defend his copyright. Some have been seemingly trivial -- as when he sued a mother who posted a short YouTube video of her baby dancing to Prince's "Let's Go Crazy."

Others have been more substantive, like his 2007 legal action against the prominent music- and movie-piracy site Pirate Bay. The case was ultimately rendered moot when the site -- which facilitated illegal downloads by posting links to files -- was blocked by internet service providers around the world.