I've heard a story from an MIT staffer that the Morris worm of 1988 was first released from a public workstation logged in as username rms, password rms.
I tried to verify this but couldn't find it. However, I did find that counter-hackers changed Morris' username from RTM to RTFM to get back at him [1], so I'm not sure he used the username 'rms'. Maybe the staffer got mixed up?
The implication is that Morris used Stallman's (publicly well-known) username and password to log in at MIT, in order to cover up his tracks. Morris was a Cornell student at the time and wouldn't have had a login at MIT at all.