Doesn't that go against the whole guilty until proven innocent thing?
People often joke that "America has the worst form of government on the planet except for all the others." It ain't perfect.
There's a "stop and frisk" law in New York now. Basically if you look suspicious they can just stop you and search your person. That seems incredibly un-American to me (an American) yet it exists, seemingly in direct contradiction to "innocent until proven guilty" and the search laws we already have on the books.