Lets fix up that list a little shall we...
CoD4 - Very few cheaters, easy to avoid.
WaW - Very few cheaters, easy to avoid.
MW2 - Overrun with obvious cheaters, nearly impossible to avoid.
BO1 - Very few cheaters, easy to avoid.
MW3 - Overrun with obvious cheaters, nearly impossible to avoid.
BO2 - Overrun with hard to spot cheaters, nearly impossible to avoid.
Now lets look at the fundamental difference...
CoD4 - Rentable ranked dedicated servers with admin control and server browser.
WaW - Rentable ranked dedicated servers with admin control and server browser.
MW2 - P2P matchmaking with no admins and no choice of what game you're placed in.
BO1 - Rentable ranked dedicated servers with admin control and server browser.
MW3 - P2P matchmaking with no admins and no choice of what game you're placed in.
BO2 - Dedi matchmaking with no admins and no choice of what game you're placed in.
Since Ghosts will use matchmaking with no admins and no ability for players to choose what game they join... It's quite clear to see that it will be another hacker infested waste of money.
BO2 - Overrun with hard to spot cheaters
I still think at least 95% of those are just a result of bad lag compensation, terrible servers and of course imagination.
More like 95% of people have no clue what to look for, so they chalk every potential hacker up to lag compensation or imagination... And since there are no stupidly obvious aimbots or wallhacks like MW2/3, it's easy to think the game is clean.
For the record, the many cheaters I've seen in BO2 cannot be explained away by lag comp, or luck, or bad servers, or skill, or even imagination...
I know this has been discussed more than enough, and I shouldn't have brought it up again, but all that talk about cheaters in BO2 is a massive exaggeration. I can't deny that there are some cheaters with hard to spot, aimbots, but I have played almost 30h hours and have seen maybe a handful of suspicious guys. And I just don't believe you have proof for all/most of your so-called hackers. I know what to look for to spot a cheater, but I only take a closer look if they give me a reason. Of course I could have missed some of them though. (I don't watch killcams.) But this also means none of the hackers is "good" enough to actually ruin the game for me. I still win most of my matches, and even if half of the good oponents is actually cheating, it doesn't even come close to cheating in Modern Warfare 1, 2 and 3.
And it's hard to believe all the "BO2 cheater horror stories" if in EVERY match at least 3 players randomly call other players (mostly me and my friends - honest gamers) cheaters.
So if there are so many cheaters in BO2, where have they been hiding? Are they non-existent on European servers for some reason?
BO2 has been a very clean, cheat-free game for me. Have seen a few aimbots early on but compared to previous CoD's this has been the cleanest. The only problem I have are with players using rapid-fire scripts either assigned to their mouse buttons or keyboard through the macro software for their peripherals. Most of these player run around with the pistol and take advantage of the OP'ness of it when using a script. I report those players but I doubt much is done about them.
Someone in this thread mentioned that MW1 was hack free? Hardly. I saw a lot of cheaters playing that game when it was a current game. I don't play it now, but a well admined server will spot and ban cheaters pretty fast.
I imagine Ghosts will use something similar to what BO2 did, a report and check system for hackers, but as usual, IW doesn't care about PC players and haven't told us much.