Ump try hards- These are people running around with Ump, which is the cheapest gun in the game, no stopping power needed. They are running around with a Ump Slienced, with marathon, lightweight and ninja and or commando or steady aim. The last perk varies. These guys are so annoying because doing this takes no skill in my opinion.
One Man Armyers- These idiots carry a assault rifle with grenade launcher as an attachment, C4 or claymores, danger close as there second perk and the last perk varies but it's usually commando. These people are hardcore campers. These guys sit in a corner where there's only one way to get in and one way to get out. They put claymores by the entrances to protect themselves and uses the grenade launcher, once their claymores are tripped and they run out of grenade launchers, they restock ammo by using one man army and do it all over again. These people usually go for nukes. Stupid campers.
People With Modded Controllers- This is pretty much self explanatory. These guys have modded controllers which allows them to rapid fire guns. For example the FAL is a single fire weapon. These guys would pick the FAL or pistols generally and make it shoot as a full blown rapid fire assault rifle which sucks. These guys have no lives.
10 prestige lobbies- These are lobbies that people make to boost your rank all the way to the last prestige. Most ten prestiges now a days are fake but they are legit ones as well considering the game has been out for so long. By the way these people try to charge 1600mp or a 3 month subscription cards. They charge because in order to create these boosting lobbies you need a modded xbox. These guys are pathetic.
Those are the things that you have to be aware of. That's about it for this section guys. Catch you guys later.