I may be picking a nit, but counting cards is legal in all casinos in the US. You are not breaking a law by counting cards, but the the casino has the right to stop providing you its service if you are, or if they even think you are (right up there with "No shirt, no shoes, no service").
Perhaps you mean that casinos in Atlantic City actually will not kick you out if they suspect you're counting cards, or they're bound by some law to allow you to keep playing?
If counting cards were actually illegal, we'd be a lot further along on our way to Orwell's 1984. You can't outlaw thought (yet).
Yes, you are correct. What I meant is that the casinos are forbidden from asking you to stop playing or to leave the casino based on counting cards. It's really in the casino's best interest though, because there are more people who think they can count cards than there are people who can do it effectively.
>counting cards is legal in Atlantic City, but if they suspect you of it they'll shuffle every hand or not let you change the size of your bet.
The fact that there's something to "suspect you of" is the whole problem. Doing the same (counting cards) in poker is explicitly encouraged, and the ability to know what cards remain in the deck is highly prized.