You should not set anyone's password over the phone. People who can't leave work during the day have until the UC desk closes at night to get here, so they should be able to make it. Alumni, students on co-op, or faculty on sabbatical can fax a legible copy of their photo ID and a FAX number to us (our FAX is 575 / 835 - 5737) and we can FAX them back an account agreement form to fill out.
The main concern here is people stealing accounts (and doing whatever). If someone calls and claims to be someone, and we reset the password, then we have just given that account away. Even if it was the right person, and that password later gets cracked or stolen, we could held to blame because we knew the password. Passwords should be a secret known only to the user who is responsible for the account, not us. There is no reason anyone here should ever know someone's password.