I think that, quite simply, the state of America at the moment leads to things like that happening, and it is begging to happen over hear too.
People are becoming more and more paranoid of crime due to the media hyping up any incidents they think will get a publi responce, like murders etc., and this media coverage has increased, while crime itself is decreasing, it seems to the public that crime is on the increase and that it is going to affect them.
This state causes overreaction when anybody suspects someone of doing something illegal. If most people saw a kid running down the street in the states with what looked like a gun 20 years ago, people would dismiss it as a toy, but nowadays, an armed responce team would confront that kidand threaten to shoot him.
This paranoia affects paintballers in that some markers DO look like real guns, and people will react badly to this. Any military link that paintball has (and it does in many peoples minds) paintballers could be seen as terrorists in training or anything else! And so people get hurt and killed because of the media and how they report the world.
Rant over