Windows 2k/XP, OS X, Linux, etc. already provide reasonably enforced password mechanisms and access controls.

Lost passwords would be a customer support nightmare. With millions of users online at any given time, I'd guess that a few hundred per day would forget their passwords.

Without role-based security mechanisms provided by the OS (such as SELinux, TrustedBSD, or Trusted Solaris), LimeWire's passwords would be pathetic. Any passwords that can be set by the user can be reset or deleted by the user.

In short, passwords would be a pain for us, wouldn't provide any real protection for you, and your OS already gives you better password protection than we can provide. If you're running Windows XP, you can even log out from one account and log into another while leaving programs running in the first account.

We could have some crazy system where you'd create a password file as one user, and make it readable but not writeable by the user that runs LimeWire. However, this would be a pain, and if we're going to require multiple user accounts and proper ACLs, we might as well just have our users use the OS's password and access control mechanisms to limit who can use LimeWire.