First, you know it has nothing to do with you or your game; you are just an object, a mental construction, at which they unload their anger; they might as well be talking to the pin-up poster on their wall (or to the pixels which form an enemy on their screen). Second, if you realize these are troubled people who feel powerless; if you have some empathy for them; they lose their power over how you feel. Here's a recent story about the comedian Sarah Silverman taking that approach and going a step further, with amazing results:
http://www.cbc.ca/radio/q/blog/sarah-silverman-s-response-to...
Also, it may be important to ask why so many young males (if that's the demographic) have such emotional problems, why so many can't process their emotions effectively and feel so vulnerable. I think we sort of take it for granted that young males (and to a degree, all males) can't process emotions and act out, but I think that's a mistake.