According to the WSJ:
In the latest patent suit to hit the smartphone industry, Apple is suing Samsung, alleging the Galaxy line of phones and tablets infringe on a number of the company’s patents.
The suit, filed on Friday in U.S. District Court in Northern California, alleges patent and trademark infringement, as well as unfair competition. Apple is seeking injunctions, actual damages, punitive damages as well as a finding that the alleged infringement was willful.
“It’s no coincidence that Samsung’s latest products look a lot like the iPhone and iPad, from the shape of the hardware to the user interface and even the packaging,” an Apple representative told Mobilized. “This kind of blatant copying is wrong, and we need to protect Apple’s intellectual property when companies steal our ideas.”
More to follow when the Complaint becomes available. It's not on PACER as of this writing, so it appears that perhaps Apple seeded the story to WSJ and Reuters.