You're right. When faced with an abomination like that the best thing to do is be armed with a video camera, record the entire "special aktion" by the Einsatz group, state clearly you are not consenting to the operation but are acquiescing to overwhelming force, ask for the authority by which they are performing the confiscation, state you will take whatever legal action is available against them individually and whoever gave the order, demand the identity of the individuals involved, take pictures of al the firearms that are stolen, and demand a signed receipt for all of them. Then, when it's over, contact the NRA and provide them a copy of the tape.
A credible threat of serious legal action like this might even cause the leader of the group to call off the assault on your home.
You start making "demands" of JBT's in the process of violating your rights and they'll just eliminate you. Their problem is solved.
So how do you stop them from taking your video camera?
They would just take your video camera and beat you senseless. It would have to be hidden.