The debris would be harmful to other satellites in orbit. Since it introduces significant risk, they cannot just shoot them down without a good reason.
Nations have become increasingly conscientious about this problem after a couple of incidents: http://en.wikipedia.org/wiki/Space_debris#Debris_from_and_as...
Must be a way to ruin the solar panels with a laser or similar. I assume non-state actors won't be able to launch satellites that use a nuclear energy source?
So presumably the US is smart enough not to mess with such groups (even if they don't actually have nuclear weapons they would still be able to do great damage with conventional explosions or even a piece of rock).
If I declare that tomorrow I'm going to launch a satellite, without going through official channels, I go to jail.
If I don't announce it beforehand and just launch, then I'd better hope I don't start a nuclear war.
Unless this goes through official channels, it becomes a ballistic missile proliferation issue, which the powers that be are somewhat twitchy about.