I do however find clauses like this absolutely abhorrent in a take it or leave it contract where the bargaining power is grossly uneven. I find it even more disturbing when such contracts are essentially presented after the fact, such as when printed on the back of a ticket or...included as part of a mandatory update for a system you purchased long ago and can no longer return.
Why not? Just because you sue them doesn't mean you're going to win. Maybe stupidly extreme sports purposely made the event more dangerous to ensure your injuries (and subsequent ratings). Signing away your right to sue puts you in an almost infinitely dangerous position.
Example of a law that makes arbitration clauses unenforceable against consumers in New Zealand unless they agree otherwise after the dispute arises:
http://www.legislation.govt.nz/act/public/1996/0099/latest/D...
In general, you cannot in the U.S. sign a blanket waiver giving up your right to sue. Waivers are generally narrowly construed to limit their scope to what the parties foresaw, and some types of waivers are just void as against public policy. For example if you sign a waiver of liability when you go skydiving, it might protect the skydiving company against a suit if you land the wrong way and sprain your ankle, but it won't protect them against a suit if the pilot was drunk and the plane crashes.
(Note: not legal advice, and possibly only relevant to the US)
Hopefully this will set a precedent.