Why is modern warfare two........?

Filled with hackers now. So this was my first time playing in like 3 months because of black ops and all, and I join a game to have guys in my lobby with fall camo on shot guns, golden desert eagles, People where able to select kill streaks with out getting any kills, a guy kept glitching it to make me and the rest of the people respawn in his area facing down so he could kill us, they made it so that in the kill cam they have different colored words, they had clan tags with more then 4 letters and no matter how many times you shot at these guys they can't die I saw one and shot 3 whole ak 47 mags into him and he didn't die.