Sorry you are wrong. Look up the patriot act, you will be surprised just how much the government can get away with without ANY just cause.
The government no longer has a need to actually notify you of why you are being arrested. The government does not need just cause to arrest you. The government can even arrest you for "possible terrorism suspicion" and hold you indefinitely without trial.
Its OK because obviously the patriot act only applies to those damn Muslim terrorists hiding out in NYC... it can never be abused in any way... right?