I had FB when it 1st started, it was fun and then as my kids got older and wanted accounts, I could monitor what was going on when I couldn't actually see them! But it never ceased to amaze me what some of their friends would put on FB, pics of them in compromising positions, drug taking paraphernalia in view or with not a lot of clothes on, totally unbelievable stuff that I was shocked at and would then tell their parents who I felt should be watching their kids, now I'm not saying my kids weren't doing these things (i am many things but i'm not naive)but if they were they made damn sure there were no photos for me to snoop and for future employers etc to browse through when they google their name .
Now they are older I unfriended them but I think I made my point enough times for it to get through about thinking before posting my son closed his account and my daughter keeps in touch with friends at uni but isn't glued to it, now my youngest has just turned 11 and begs for FB but I won't allow it( she did go to a party when she was 8 and the mum made all the girls sleeping over FB accounts!! I went mad, and it caused a lot of trouble in our house)it's full of inappropriate stuff but most of the kids in her year 6 class have it
Mobile phones have etiquette in our house too, no phones at the table, no answering the phone when I am talking to them and when they were younger they had to turn their phones in at bedtime! God I sound like a bit of a tyrant! Ha ha good!