That sucks man.  What stinks even more is that legitimate guys like you get criticized because of the amount of illegitimate dudes who are actually using rapid fire.  I never bought into that until I went onto one of those modding controller sites to buy a customized controller for my best buddy for his birthday.  I got it engraved with some illuminating shoulder buttons with a chrome looking shell.  The wierd thing was that before check out I had to uncheck the box for the Rapid Fire button, because the feature was included in the base price.  I'm glad I noticed because he never would have used it with rapid fire, but that just shows you how accessible it is.

Anyway, keep tearing 'em up man, and don't pay attention to it.  People like to say you're cheating just to make them feel better about how much better you are then them.

Its very easy to tell the difference by the consistency in the firing.  You can be fast, but not completely consistent in your firing, where as a mod will sound completely consistent.  I get people often accusing me because I love the MK, but if you watch/listen , its obvious Im noobish.

I think the accusations of using a modded controller are their attempt at justifying getting owned by you.  Keep up the good work!

I have been accused of it a couple times. Which is weird because I personally think I shoot very slow. But I can always tell if someone has rapid fire. It's not that he shoots really fast(some can just do it), it's when he shoots fast with the same amount of time between each shot. Controllers nowadays are starting to make it harder to spot though, letting you put burst fire on and somehow getting past game features that are supposed to stop it(World at War being a perfect example).