[rationalist]

Allowed, yes. Doesn't mean it's right or even preventing tyranny. You aren't insulting the people making or passing the laws/rules/etc, you're insulting the people acting on those laws/rules/etc.

There is no overstepping authority if they actually have that authority. That doesn't mean they should have that authority, but they do, and thus they're not overstepping it. They're just using the tools at their disposal to get back at someone who is being an ass.