i remember a debate competition that i participated in ,many years ago.
Though my ideas were not very well formed at that time and i was naive, one point that helped me win was
Will you let your kids go out to market/places/trips alone without supervision?If not then do realise that internet is WWW world wide web,its teh whole world out there.
Parents need to follow the same set of procedures /safety measures and supervision when they let them go.
Like parents teach kids to not talk o strangers , similar thing should be followed onlin also.AT the end of teh day, its the respinsibility of parents to keep a check.
Some children are ready early(maybe the kids rganising indi blogger) som take time. Ultimatly its teh upbringing and parental supervsion that is the utmost important thing.
Online communities cannot really ban users ,but yes their resposnibility is to have enough protective measures in place in case abuse/bullying/exploitation is reported. They need to be proactive, something like facebook has started doing.