Dude I got the answer to your problem, Just call up Sony and explain the situation to them. Leave out the part that you have it on 4 friends PS3s, though. Tell them that you sent in your PS3 for service, and they sent you a new one and you forgot to deactivate your account on the old one. They can do a mass reset on your account at their level. Which means every PS3 that has your account will get deactivated. Then your friends can go and manually re-activate your account on their PS3s.
I have already done this, since, I have 2 PS3s and my brother has one and I have been through a couple PS3s myself. So let me know if you have any questions.
EDIT They can only do this once, they will mark it on your account, so from here on out you will have to remember to deactivate it yourself, or pick your least favorite of the 4 friends.







