I'm constantly getting knife lunges that don't kill people. I'm constantly the target of RC-XD's. I'm constantly being killed by people that know exactly where I am even with ghost. I'm constantly having to put more bullets in people than others have to put into me. I'm constantly not being able to shoot down spy planes. I'm constantly getting paired with retards. I'm constantly being killed by people that aren't on my screen. I'm constantly being killed by people in areas that I can't shoot into but they can shoot me. I'm constantly being spawn killed. I'm constantly having people spawning behind me and killing me. I'm constantly having more recoil than others. I'm constantly being affected by flash or concussion grenades longer than others. I'm constantly being paired with people that think every single gametype is Team Deathmatch. I'm constantly getting killed by grenades when I'm not even in it's blast radius.
This is just what I can come up with on the top of my head. If I were to actually list the things that constantly happen to me, the next Call of Duty would be out by then.