The solution to preventing crime is NOT to treat all free people like suspects.
The police tactic of "stop and frisk" is abusive, because as a practice it pretends there is no such thing as the Fourth Amendment.
They, of course, make claims that their abuses are for our own good.
For those of us who would prefer not to suffer quietly the abuse of our rights, there are new ways being developed for documenting and reporting abusive encounters with the police.
Here's one of them...