Problems with my 16 year old son's probation officer?

Sounds like you have your hands full. In relation to your older son I guess you can steer him in the right direction but at 16 if he wants to screw up his life there really isn't alot you can do about it. In terms of the Probation Officer there is probably alot you can do. All government officials are guided by very strict code of conduct. There will also be a very well defined chain of command at his workplace and finding his supervisor shouldn't really be too hard. I think a word in the ear of his supervisor probably wouldn't hurt - I doubt the PO is going to do you any favours so what do you have to lose by saying something to his boss. You'll find that if he really is that much of a pain the people he works with (inlcuding his boss) probably know exactly what he is like. I think you have grounds to indicate that his behaviour is both aggressive and inappropriate. Hopefully they ign you someone else and your son cleans up his act!