What are the things you find annoying in MW2?

Basically i think that quick scopers are not that big of a deal since u wont always get one hit one kill because of people using second chance(noobs) or last stand or whatnot.its also hard to find the center of ur screen to actually do it and takes lots of practice.U like it when ur actually doing the quick scoping but hate being at the receiving end of it though.thats why most people hate it.the game is supposed to be fun and btw do u see people actually doing any of the real stuff their doing in afghan?