Yea it happens a lot but I don't think it is as much people trying to hide personal attacks as people trying to make sure their post are not taken as personal attacks. You can generally tell when somebody is being a wise ass and when somebody is actually making a personal attack, but a lot of people take things personal they shouldn't, thus the smiley face at the end to signal it's not a serious personal attack. I'm sure this does get abused, and I find it humorous that so much emphasis is put on whether there was a smiley face at the end of the attack or not, I'm sure the "But I put a smiley face at the end" defense would not hold up in court. I would guess you would have to view every post on it's own merits whether there was a smiley face at the end or not, if it offends then it offends, report it.