[morrow]

Nobody is suggesting that drivers should be free to police themselves as far as the legality of the circumstances of their driving. This is simply a matter of freedom of speech -- if you see a police car doing radar on your drive home, and call your friend (after pulling over ;) ) who you know will be driving this way, to warn him, are you breaking any law?

The principle being defended here is that you are free to share that information under the 1st amendment, however the method of sharing may be performed. It's the reason being a member of the KKK or the Westboro Baptist Church and saying hateful things doesn't automatically make you a criminal. Whether you agree with the speech or not shouldn't affect it's possibility to be spoken.