Well, I don't have a PS3 now but I'll probably buy it (with GT5P) this month.
However ... I'm almost every night playing TRD3 online and I can't believe that GT5P lacks all the neat features that "old" game has.
When I host a session, everybody is welcome, but if I spot any driver shunting others deliberately (unless we're playing "cops and robbers", but even for that there are rules to be followed), or driving backwards or just NOT racing, I can (during the race) just hit the START button (my car is taken over by the AI), select the "driver" in question and "kick/ban" him with immediate effect.
Anyone that ever played TRD3 online knows how it works.
I just hope PD get things straight soon ... reading these many posts isn't making me exactly eager to go online with GT5P.
Let us not forget it is a game, a toy, not an official RAF FBI CIA MI5 police army simulator or F1 training course, its for fun. I'm glad some of you are not my dad, Relax boys.
It's a RACING game, cmdocker, we're supposed to use it to RACE. Following your logic, I guess you don't mind - while playing any card game, or whatever game you like - that other players just don't follow the game-rules and make it impossible to continue playing properly.
btw, I have a 11 year old son also, and he also plays TRD3 online. I think he likes me

, but I can assure you that I told him that there were three rules he must follow, or else, no online gaming for him:
1 - to race fairly;
2 - to apologize if by any mistake he crashed into others (in TRD3 you can talk to other players, using headsets)
3 - to not respond with stupidity to the stupidity of others. If he's hosting, ban them, if he's not, and the host doesn't ban the "crashers", just leave the sessin and create another one.
I think he's getting along fine, and I have received compliments about my son's skills and decent driving from many of my usual TRD3 online "friends".