glitches

Are they fair, is it cheap to use glitches when gaming online? Personally I think its the cheapest thing to do, thats not how the games supposed to be played so dont cheat. Playing call of duty modern warfare 2 was frusterating for a while to say the least. People running around with a javeline, getting more than a few care packages, those overpowered 1887's with incredible range. I stopped playing for a while till they came out with a patch, but still it was pretty stupid playing with 14 year old kids manipulating the game. I know some people say its in the game, you might as well use it, but not when you have to hold x, switch grenades, then throw a knife, the game is not supposed to be manipulated like that. But everyone has their own opinion, and think of things differently, so is using glitches online cheap or fair play?