I guess it is kind of a slippery slope, indeed. There are probably ways in which it could work only as intended (hardwired chip or whatever), but allowing other people to block your thoughts is only a couple of steps from turning you into their puppet.

As for simulation as though crime, I am not sure. If they need to peek inside your brain to check if you are not running illegally constructed internal simulations, the government can just simulate a copy of you (with a warrant, I guess), either torture or explicitly read it's mind (either way terrible) to find out what is going on and then erase it (I mean murder, but government does it so it is kind of better, except not really.).

Your approval of such measures, probably depends on the relative values that you assign to freedom and privacy.