I think these daredevil practitioners of natural selection should win a group Darwin. On the other hand, perhaps they are just pursuing a hobby, albeit dangerous, and therefore not eligible. It is true that people endanger their lives in these extreme sports, but look at it this way. Millions of people have jobs that place them in copious amounts of personal danger every day. Now some of these jobs provide cures for diseases, and alternate forms of fossil fuels, thusly leading to the greater evolution of the human race.
People do dangerous things as an occupation because they love their work, and they get paid.
But what if they love doing something so much they don't care about getting paid. It's a hobby. Leave them alone. Giving honorary darwin awards to groups tempts us into assigning it to people we beleive might be doing stupid things, and that may respond to prejudice and not to logic. It's supposed to be natural, unbiased, selection.