Prophylaxis Plus

Prophylaxis Plus is a program that forces the user to enter a password whenever the Mac is turned on. It's simple and effective startup security; most users can't bypass it, but it's not impossible (or even that difficult) for a determined hacker to defeat Prophylaxis Plus. The only way that I have found to bypass it is to start from a different System file, such as that on a System disk, so if you lock your floppy drive, or are convinced that your enemy doesn't carry Mac System Disks around, it's probably pretty good protection even from that determined hacker.