While that is something we "can" do to help, it is incredibly cumbersome. They finally implemented a right click to blacklist option, but failed to implement a right click to report option. I find this a bit odd. Many MMO's have a report right click option that automatically reports the text to the GM's and adds them to your ignore list at the same time. Not every single one of the 10 RMT tells I get a day needs to have an explanation about it sent to the GMS. Reporting it through a click really should be sufficient and added by SE.
As it stands I just blacklist them but do not go through the hassle of filling out a cheating report each time. It is unreasonable for customers paying for a service to be expected to do that on something as rampant as RMT tells.