It's not really a question of legality. It's legal most places in the US to be on a hands-free device while driving. It's a question of safety. It's NOT more dangerous to have the controls locked out because you shouldn't be messing with them in the first place to even notice they're locked out. I understand you may have a passenger or whatever, but that's the nature of things. Blame the retard teenagers who can't stop texting and keep crashing into shit.
Plenty of cars DO lock out all stereo controls while up to speed, and you SHOULDN'T be messing with the radio while moving either. People do what people do, but doesn't change the fact that it's unsafe. IMO, nobody has a right to complain about it.
But that's all I got to say about this, unsubbing from thread