The police have ALWAYS been given the tools to do this kind of thing by the courts and parliament. (in all of Europe, at least.) There are loads of offences still on the books that could mean almost anything, but which can be used as grounds for arrest. The police have ALWAYS used their 48 hours of custody to remove certain troublemakers from certain areas under every type of government. Taking away your ability to shout in the streets for 48 hours is not MUCH of a restriction on freedom of speech. Get a blog and millions can read it, but nobody will. Most people don't have time for politics, and the majority won't until resources are no longer scarce.
People, if you support Pres. Obama you have to go along with statism because he is one. Supporting him because he is the "least worst" even though you hate any statism is stupid. If you don't like a big government, support someone else.