First off, I'm not going to bother posting this on the DCUO forums as it will just get taken down. However, I want to spread awareness of some people using macros that I've encountered in arenas.
I've been doing a lot of 1v1 Lair Battle over the past several days and I've encountered a couple of people over the last couple of days whose weapon attacks are abnormally fast. They use Martial Arts (MA). However, unlike normal MA users, they attack with almost 1.5x the speed of normal MA users. Also, they use only weapon attacks and no powers.
There is a key pattern to the fights which I've observed. Some fights,
they keep the macro turned off and the damage output feels within normal
parameters. However, some fights when they turn it on, the attacks are
unnaturally fast. I don't have the video clips to prove it. Just
gut-feeling from my numerous fights with people in arena.
The 3 people whom I've encountered doing this abnormally high damage are Airsupreme, Xtantha, and Not Rooney. Airsupreme and Xtantha are hero characters on US PC. Not Rooney is a villain on US PC, who also goes by the name of Rooney on heroside. Airsupreme has a track record among both veteran heroes and villains as a macro user and speed-hacker. He's been handed numerous suspensions but hasn't been outright perma banned yet. If you see him on hero side, keep in mind his past record. He's an embarrassment to whichever league he's in.
Someone already posted some detailed info on detecting speed-hackers back in Dec 2011.
His description on points 1 and 4 matches my experience very closely.