The capability to record gameplay is one thing, hiring employees to look through gameplay of accused cheaters is another. COD has millions of players, most of whom play online and many of whom probably report players for nothing all the time. There's people here (frostzorn, distiny) that are in the top 20 leaderboard, along with many others, that have very clearly hacked and IW hasn't done anything about them, so I'm doubtful they are sifting through gameplay videos of people who get reported. Maybe if someone gets like 100 reports they would take a look, but judging by how they govern the leaderboards, I wouldn't be too worried.