First off, I want to know: Who is keeping up with the Frag Cup currently running? For those who don't know what the Frag Cup is, it's a tournament being hosted by Machinima .com, and there's $5k in prize money. Professional gaming teams such as OpTic are competing.
Speaking of OpTic, they were disqualified because at least one of its members, Dtreats, was using a 4-perk mod that replaced the Grenade slot with the Hardline perk, and had a "Gold Desert Eagle" equipped as a secondary weapon. Whether or not the Gold Desert Eagle actually does something I do not know, but it's not normally accessible in-game, and clearly the 4-perk setup is either a glitch or a hack.
The video is here: http://www.youtube.com/watch?v=3ATi2mNh4VI. Pause at 0:21 and look at the weapon setup, it's very noticable.
On the topic of glitching/modding perk setups such as this, have you encountered anyone doing this online? If so, was it the same or different from this example?