I'll expand on my previously-stated views:
The premise of the law isn't the problem, it's the ambiguity. "Reasonable suspicion" combined with "lawful detention" gives too much leeway to the government for my liking. When it comes to civil liberties, I prefer to err on the side of the people rather than the government. Strange how I'm the one arguing for restricted government power and you're arguing for the stronger, wouldn't you say?