Because, as someone has already pointed out, it is a free country, it isn't against the law, it does not go against any terms and conditions imposed upon teachers (except, it would seem, in very rare cases where a Facebook contract has been signed
) and most of all because it is none of your goddamn business.
I object hugely to the suggestion that I must alter my behaviour outside school in any way, shape or form because 10 year olds may have lied to get themselves Facebook identities and their parents either don't know or don't care.
My settings are private, but that isn't because children might see my photos, it's because my private life is just that to me. But should I change my mind, then I fully reserve that right.
Glad you have dropped the pretence that you were ever joking, Rob.