Who's going to decide whether you pose a threat to public safety and what criteria are they going to use to decide whether to scoop you up or not? Do we leave it up to the police to decide?
There is a long, long list of types that the police don't like whether they are doing something illegal or not. Thirty years earlier, they would have filled up their cells with gay people using "public safety" as their criterion.
There is a precedent for this sort of foolishness that most of you won't remember. In October 1970, after the War Measures Act was invoked and suspects with links to terrorism were being arrested by the hundreds and being held without rights, the mayor of Calgary had the police there arrest groups of Hippies under the umbrella of the War Measures Act. What threat did the pose? Well, they had long hair, dressed funny, listened to loud music that was clearly not Christian and they like to smoke dangerous drugs. They were obviously a part of the insurrection in Quebec.