is there any way to prevent users/programs from typing in dozens of passwords a minute? What should I code or what mod should I get for this?
Search google for 'brute force protection' or something similar. You could always code something that block's an IP after 3 failed attempts for 15 minutes or something.
Check this http://forums.invisionize.com/index.php?showtopic=83271 As you can see, it is made for IPB 2.0...so if you have 2.1, you might want to read around for compatibility...even if you have 2.0, I'd definitely test it out first, as something like this could really mess things up