Not all social networking sites are bad - but I have no objection to even perlmonks being restricted to children whilst at school.
If PM is restricted to children whilst at school, then how will we get at it? ;-)
Oh, I guess that's not what you meant to say. ... You know, laws can be like that too. They sound good and well targeted to what you want, but they end up doing other things as well, and sometimes don't accomplish what you want. Sort of like programs, but with no debugging cycle.
I'm taking no position on this law, since I haven't had time to look into it yet, but I do have one relevant datapoint.
My son was 13 and had a mild interest in Perl (he's had little pushing from me.) He had a simple perl question, and a friend of his directed him to a perl-specific IRC, since everyone that age knows IRC. He said he was impressed at how nice the people were and how quickly he got help. Someone was mildly disparaging of his naive question, but others said "Hey, the kid's gotta learn." He did learn.
His positive experience, the gift of encouragement, not just knowledge, was the primary impetus that brought me to active participation here at PM.