Not sure about the law ...
... but on my way home from work, a car dealer has a bluetooth push, which tries to send a picture of a car.
It is ****ing annoying, as it makes my headset beep, as though I've received a text. If it wasn't for the fact I am waiting to be bluejacked by Paris Hilton, I'd set it to "refuse" push messages, instead of "always ask ....