So many trolls, cheeky and goady fuckers these days! Advanced Search can be helpful in identifying a first time poster - but given how frequently people name change, or the fact that often people name change for one, specific post, sometimes a long-term poster can seem to be a first time poster. Hence they may come under suspicion too.
Could you add, underneath the info on the right-hand side, where it currently has 'message/report', the month and year that they joined MN?
I realise that being here for a while doesn't preclude trolling (unfortunately), but it's much more likely that someone posting a CF/GF/Troll thread, who only joined this month, is not going to be a genuine poster.
Most other sites seem to have this kind of information. I think it would be really useful.