Caffeine OD

Interesting, but questionable (at best) website:

http://www.energyfiend.com/death-by-caffeine

According to the above website, I could consume over 170 cans of Red Bull before the caffeine content would cause death. If that's the case, why have I been up since 4:45 a.m. after 3 Shreks (redbull with UV blue vodka) during American Idol last night?!