It is being reported that they are federal officers but handling protests should not be in federal jurisdiction. They are not identifying themselves, aren't wearing any labels and drive in unmarked civilian SUV's. They are arresting people without a statement, and driving them away in rental vans. What they are doing could be done by just about anyone who owns a weapon and camouflage pants.

At the very least tolerating this sets the precedent that:
Anyone can be arrested for any reason.
The command of anyone dressed up like military has to be followed.

I think most people will agree that this is problematic. I think it's a lot more than that. This is the time you should start to panic if you live in the US. I think it's something that needs to be fought back immediately. You cannot allow fellow citizens to be arrested by unidentifiable and therefore unaccountable forces.