timothy from the great-to-be-top-of-the-list dept.
illectro writes "A study on site availability by monitoring service Pingdom shows that in 2008 Twitter greeted users with the 'Fail Whale' for more than 84 hours, almost twice as much as any other site. At the other end of the scale imeem and Xanga managed less than 4 hours of downtime for 99.95% uptime. Myspace, Facebook and Classmates.com were the only other sites studied which managed to stay up more than 99.9% of the time."
Computers are unreliable, but humans are even more unreliable.
Any system which depends on human reliability is unreliable.