I was actually looking around on the forums trying to figure out where to put the video I took of exactly what you described.
When is this junk going to be laid to rest? Bad enough you can't enter a city without a wall of text spam and the random tells from the "hacked" players trying to sell gil. Speaking of which, HOW many fools are going to keep going to these sites, getting hacked and then enabling new gil spammers? It's like a chaotic circle of dumb.
TL'DR: Caught 2 players on Balmung server, outside of Fallgourd Float around 2:30pm EST, teleport-farm hacking Banemite mobs like there was no tommorow. Towards end of video, they also appeared to be speed hacking with a much higher run speed than sprint.
http://www.youtube.com/watch?v=V-i2bX4OcZ8