I know that Warcraft used to (haven't played in forever) have a big cash for gold problem, and it seems like FF14 has it's share as well. Players can sometimes get annoyed at having to block spammers every 10 seconds, and wonder if the developer actually keeps track of that stuff, but the FF team just recently threw out a large serving of Banhammer. Looks like they take those RMT reports seriously, and even nailed some people who might have been on the buying side of this.

Actions Taken Against In-Game RMT & Other Illicit Activities (Feb. 9)