I have witnessed somethin' like this before whilst in-game. I've seen users blatantly state their actual names (both first and last), a vague description of their hometown, their school, etc. It was pretty heinous to say the least. It dumbfounds me how vulnerable some individuals can be via say somethin' reassurin' and crafty to them then bam, they're willin' to give ye' a bit of their personal information. It more so bewilders me as to why their parents and/or guardians have either failed to inform them of the dangers of social media or the fact said minors fail to listen to their guardians' warnings. Another enigma I suppose.
Like stated before me, ye've did the right thing in warnin' him/her about the dangers of sharin' said information.
First, what is a young child doing on MySpace? Or any social/video/any site like that? Children that age shouldn't even be on the internet at that age without parental supervision. That's just logical. But, parents seem to be lacking on this... I'm not even sure they tell their child internet safety.
No one, even adults should give out addresses, phone numbers, or anything personal of the sort. I don't see anything wrong with gender and things like that, but truly personal information is just wrong.
I've seen people in FH literally, say their name and things like that. Why would you do that? Maybe because they lack the knowledge of what people can do by just knowing that?
I don't know, but anyways, like Feareh stated, block the person. I'd probably report them.