You keep your enemies close to keep an eye on them. By not making any arrests right now and letting them continue with their crap, they get a false sense of security and their actions and words give them away. There are tens of millions of Americans who think these assholes have not only done nothing wrong, but they consider them heroes. To arrest them now would only bring down more hate and discontent on those that are dealing with it all daily. Like they say, never interfere when your enemies are busy destroying themselves.