Actually, you only need one monkey if he has an infinite amount of time. Or an infinite number of monkeys if they have only enough time to type one item (e.g one play or one essay, etc.) Ten thousand monkeys would not noticeably reduce the required time. (Infinity divided by 10,000 is still infinite.) So for practical purposes, you're better off with an infinite number of monkeys and a week or so for typing, than with one monkey or ten thousand monkeys and an infinite length of time, since in the latter case you would not live long enough to see the result.
Unless they were typing the script of a Michael Bay movie. That would take ten monkeys about two weeks.
Threads like this are why I keep coming back to PC. If the author had been serious, he could have also mentioned the legions of closeted hippies that cut their hair, stopped smoking, and infiltrated the "system" to do God knows what kind of damage. Nobody I know of course.