Not one to worry about name calling normally, but checking my son's phone I've found a text this evening from an unknown number informing him that someone at school has replaced our surname with what i consider to be the worst expletive around (sorry if this offends but the word used is c*nt). This now being is new name. Nice eh? Now I know he's no angel and am sure he uses words I wouldn't want to hear, but I'm concerned that this has come from a number unknown to him (as its not a contact of his) and could be the start of something nasty? What advice can I offer him? He's a bit of a geeky type and quite bright, but wouldn't hurt a fly.