I don't want to hang out with kids in Second Life. I especially don't want to hang out with kids who I think are adults because they have accepted the TOS and are in Mature or Adult sims. I don't care what their reasons or motivations are.
Child avatars don't bug me. I am aware that they have adult operators. I find a child operating an adult av and attempting to engage in adult activities a million times more disturbing.
Once upon a time I was involved with a young man, thankfully over 18, who referred to me as his Patrona. He was/is a fantastic photographer, a good friend and great company. One day the penny dropped and it suddenly became crystal clear to me that he was using SL to avoid real social interactions and growth. It was his haven to avoid taking chances and moving forward. It was a way to avoid crossing the bridge between university grad and real adult life out there in the big, bad real world. He was too cool, too handsome, too funny and too brilliant to be held back by anything, especially something as silly as Second Life.
He took that promotion and moved to the city. He met that beautiful girl at work and they have started a life together. He never comes into SL anymore, but we are still in touch and I smile every time I think of him. Knowing his potential, I would have been a very shitty friend indeed had I encouraged anything less.
I can't stop kids lying about their age when coming into SL and accessing adult areas and activities. It was a situation we faced before the merge of the teen and adult grid, and one I dreaded and expected to be a problem after the merge. It hasn't turned out to be much of an issue. Maybe because SL wouldn't and shouldn't be a viable alternative in the social life of the average 16 year old. I suspect most of them would find it incredibly lame.
I can avoid General rated areas, which is the only preventative measure, if we are all following TOS to steer clear of the kiddies. When I think of all the things a young person can and should be experiencing in the real world, SL would not be a habit I would help develop.