> Heads up - the GPL is a copyright license, not a contract with users.

A “license” (copyright or otherwise) is either a gratuitous license or a contract, and, while there are some important legal differences, gratuitous licenses are generally enforced under contract principles. So, generally, contract law applies to licenses.

Generally, the FSF and related groups have argued that the GPL is a contract license with mutual consideration, and I believe this has prevailed in some cases (it is possible for it to be true in some cases but not all, since contract depends on specific facts between the parties and not the written terms alone.)

> Ironically, the SFC I think tried to file their case in state court. Copyright law is a federal matter.

One principle of contract law is that the existence of a contract limits parties to action for breach if the terms are violated by the other party, not whatever action they would have on the underlying rights without the contract.

SFC didn't say that a GPL violation isn't a copyright violation, obviously it is. The Vizio lawsuit is simply an attempt at an alternative approach to achieving GPL compliance. There are a lot more ways to do that than just suing over copyright; for example you can get customs to seize the non-compliant devices as they enter the country, which Matthew Garret did to some Android tablets many years ago. The Vizio lawsuit is their first attempt at expanding the variety of compliance actions they can take. The Vizio lawsuit is kind of brilliant, since if they win it means that anyone can sue for GPL compliance, not just the copyright holder, which should make compliance much more common.