Controlling who you receive tells from AND getting a right click->Report functionality would effectively neuter RMT in this game. The former would just annihilate /tell RMT spam entirely (especially if that setting had a few options like Everyone/Friends List/Free Company/Linkshell), and the latter when combined with blacklist would suck all power away from the annoying wastes of space who park their lv1 characters by market boards and spam in /say. Only real concern then would be friend requests.