[legion]

Time limits are placed in sensitive programs (like you can only log on once every 15 minutes) to prevents brute-force hacking. If there wasn't some kind of time limit, a hacker can get a program to keep submitting password guesses until it finds it. Locking you out of your account after some number of bad logons accomplishes the same thing.

Without one or both of these, it can take a hacker a matter of minutes to break into a system.