RMT tell spamming is really horrible. The only thing that is worse is the only way I've found to blacklist them via PS3.

Start -> Social Lists -> Blacklisting -> Add New -> Enter Name -> Confirm
(May of missed a step, doing it in my mind from memory..)

The problem is RMT spammer "Aillilli lilliliil" will send me a very lengthy message, hiding the first line with his user name--The blacklist window and the chat window cant be displayed or function at the same time, so I will have to drop my controller & write it down.

I would prefer to hit select on the chat window, hover over "Aillilli lilliliil", hit square, and a blacklist option show up on the list that already exists.

Please & thank you :3

EDIT:

I tried "/blacklist Aillilli lilliliil" to no avail, and even if there is such command--starting any sort of chat in the chat window still scrolls you down to the bottom of the pane, hiding their name if they send lengthy messages.