Towing Issues: wondering if there is a law about, seat belts, taxi service

Question
I was wondering if there is any laws regarding people riding in thier car on a tow truck in california while it is moving?  

Answer
while general thoughts are that they have laws about this issue, I have not seen or heard of an actual law about it.  I have looked for one before and know of none that are there.  Is it safe, HECK NO,  does it look professional  HECK NO..

Would I do it if I had to, maybe to get something and someone off a dangerous roadway, but that is it.   I have seen the videos on the Internet of this, I am appalled at it and would love to give the driver a good safety talk.

But one thing to remember is that its hard to provide a towing service and to add on a taxi service at the same time when you have to many passengers for the vehicle that is doing the towing.  By law in most states you are only allowed to carry as many people in the vehicle as you have seat belts for..