hedwards: I think your confused, the OP was wanting to know about posting gameplay footage online, not posting copies of the games for pirates.
But, yes, breaking the DRM if there were any would still be a violation pretty much everywhere.
wodmarach: He seemed to assume because its DRM free it's ok to violate copyright from the way his question was written "is copyright allowed to delete my video or is it just like Minecraft?" that kinda hints he thinks that theres no copyright on minecraft
I'm trying to figure out how to explain this... this is really how most of the world sees it. If you tell them they "own" it they're going to think this type of thing is okay. And really, 99.9% of the time it probably is, or should be. I never see anyone sell tickets and project their latest DVD hit from Walmart onto a wall.
People don't "get" copyright. They do get the idea "Don't you think artists should get something for their hard work" because hard work is something everyone understands, well, nearly everyone. But they don't get copyright.
EDIT: And when you think about it, it's fairly nuts that you're trying to convince people that you sold them a sandbox (aka video game) to play in and they're somehow not entitled to show the world the sandcastle they made (aka the experience they created in the video game).