Social security/minor child...important?

My 17 year old son was recieving s.s.d. benefits due to a mental illness.
He decided that he no longer wanted to live at home and moved in with a friend.
Apparently I cannot force him to come back home in my state and have barely any rights.
The day after he left he went to social security and had his payee changed from me to his friend.
He only had his permit, but no s.s.card or birth certificate, and no statement from me saying he no longer resided with me.
I could care less about the money as it went to all of his expenses anyway, but this doesnt seem right to me.
He could have been anybody, and brought Joe Blow off the street to portray his new payee and they changed everything for him.
I have yet to contact them about this matter, but I am angry that the system made this such an easy task for a minor with a mental illness.
Is this a legal thing? Should it be that easy for him to do?

Also, he originally recieved this due to my information and income and it took MONTHS!!!
It took him a matter of minutes.
Can they still use my info on ANYTHING since he no longer resides with me?
Come Monday I am going to raise he** with them, but want some advice or info first.
Thanks

If you are involved in advocacy, have you considered checking in with NAMI?
It can be a laugh when someone is NOT a parent to a child with psychiatric illness. I would agree with the fine line question between one who is eligible for ssdi.. and if you need to take steps to petition for incompetency as an adult. Or, what are they qualifying factors that he can be designated as an "endangered" adult.
I don't quite understand that you are (to my understanding) still legally responsible for him until 18.. but the state allows him to move out at 17. (yes, that's a whole nuther can of worms, going beyond someone on ssdi).
I was also under the impression that ssdi involves you having authority UNTIL AGE 18, so it makes no sense at all that they allowed him to change the payee, whether he lives at home or not. I'd be as upset as you are.
I do understand the fear that any parent faces, with a child who can refuse treatment and/or meds at 18, and leave. I went through it, with a bipolar daughter. One fortunate thing in my situation is that WHEN STABLE, she fully accepted her illness, even talked about going into advocacy herself. For the 2 months or so before her 18th b'day, she had meds but faked taking them, and of course, destablilized. Between 18-20, it was pure hell, knowing that there was nothing I could do, in terms of intervention. After one episode of becoming homeless, it was a real wake up call for her. She is still not back on meds, but she IS working to get her life in order, and talks about getting back on her meds voluntarily when she can afford a new pdoc.
My email is open if you need a shoulder.

if in your state he is allowed to move out at 17, then their is nothing you can do about it!! he had proof of who he was! you should be helping him with this transition and give him what documents belong to him, if not your going to alienate him and he will not have to keep in contact with you, cut the apron strings!!!

I do know of what i speak!!!!!!!!!! now his check will get adjusted according to his life and not yours!!!!!