For starters they can force host. Once they force themselves to be host they have all kinds of power. They can grant abilities to just themselves, to individuals of their choice or to everybody in the lobby. Some of these abilities can be implemented in small enough increments to give a slight advantage to those they were granted to or in large enough increments to make it completely obvious to everyone in the lobby. These abilities include but aren't limited to jump height, speed, field of view and XP. Other abilities can still be granted to people the host chooses but they're either on or off. Some of these abilities are unlimited ammo, no recoil, steady aim and colored boxes that indicate where the opposing players are. This is a software based way of cheating where the software resides on the modders PC and communicates with his/her xbox. I've listened to interviews with theses hackers and they seem unstoppable at the moment and there seems to be quite a few of them. The have no concern about being banned due to the fact (according to them) they can unban themselves at will. They hide behind servers dedicated to this type of activity.
Another big thing now are the various attacks that hackers/cheaters can do for an advantage. These are the DDOS, DOS and DNS attacks. In very simple terms they flood your modem with information slowing you down thereby causing lag on your end. If they're host they can attack individual IP's. If they're not host they can attack the host IP.
Then of course there's the lag switch that probably needs no explanation.
I've had GHOSTS for a little over a month now and I've run into everything I mentioned above. From reading this forum I see a lot of members saying that they've only run into a cheater on a rare occasion or not at all. How do you know? For the people that have their suspicions when they see a character moving a little too fast or shooting with no recoil or seeming to know exactly where you are I say you may be on to something seeing as how these abilities can be implemented by cheaters. I personally think there's quite a few people involved in these activities in this game. I'm placed in undeniably modded lobbies a couple times a week. More often than that I'm placed in lobbies that I suspect to be slightly modded. Although, the majority of the time I think the lobbies are free of any modding. I witnessed a player get booted from the pregame lobby because he had a disagreement with another player. The player told him he was going to do it and when the booted player was midsentence he was gone. The player and his party laughed like it was cool and I got out of there quick. But, how many other players has that person and his party booted or DDOSed? I wonder.