Look, I have no patience for libertarians, but I DO have a problem with all the cameras the police are putting up here in NYC. If they can prove somebody is using this product to deliberately break they law, I say "have at it." Otherwise, the only thing outlawing this product will do is encourage somebody else to sell it in an art-supply store under another name.
Take a look at a NYS plate from different angles. There are three nearly invisible data stamps stacked in the middle. I think they hold all owner data necessary to track the vehicle at tolls and with those light-cameras. My bet is that the paint blocks the reading of that stamp.
We lost a family member to an MVA. And we've had other family members and friends injured by people running stop signs and red lights. The gov't can regulate their little hearts out as far as I'm concerned. Since I happily obey the traffic laws and think other people should, I don't mind a bit. I think it's a pro-life position :)
If they outlaw paint, only outlaws will have paint.