Yep, it was a long time ago, and he was one of those "old net boys" who worked on the early ARPANET, but I won't say anything else that might identify him.
I have another naughty friend (not the same person) who worked at SRI-NIC implementing and maintaining the ARPANET TACACS database, and as a personal favor, he created our mutual friend Devon his own ARPANET TAC card.
So Devon's free vanity TACACS account was named "DEVON", while most other accounts like mine were something ugly like "DH32", using initials and numbers. One day his boss summoned him to his office and showed him a print-out of the TACACS accounts, with "DEVON" right at the top, and asked him who the hell that was. He sheepishly prevaricated that "DEVON" was actually a control code to turn the printer DEVice ON, which accidentally got printed at the beginning of the list because of a bug in his program missing an escape code, and he would fix it right away. And that's how Devon lost his TAC card. We still tease him about his name as a printer control code, and call him "DEVOFF" when he talks too much. I'm pretty sure his boss knew what was up, but just let it slide.
Network security was a lot different in those days. TAC cards only happened later when they finally put passwords on the dialup TACs/TIPs -- you originally could dial up and connect to any host on the ARPANET without a password, then you could ask nicely for a free tourist account at places like the MIT-AI Lab. It didn't even require any social engineering, just being polite and curious, reading documentation, and following instructions.
I asked BBN nicely about the TIP manual, and they helpfully mailed me a free hardcopy of the "Users Guide for the Terminal IMP", which documented how to take control of other people's sessions and even divert their output by prefixing @ commands by their terminal number! See "Section 5: Unusual uses of the TIP" page 5-7, "Setting Another Terminal's Parameters" and "The DIVERT OUTPUT Command":
https://usermanual.wiki/Document/ADA014398UsersGuidetotheTer...
The guy who originally wrote that TIP manual in 1971 was none other than Will Crowther, who also developed Colossal Cave Adventure with Don Woods! You're in a twisty little maze of IMPs, all different.
https://en.wikipedia.org/wiki/William_Crowther_(programmer)
https://en.wikipedia.org/wiki/Colossal_Cave_Adventure
ARPANET Psiber SPACE (circa 1986): This is the network of IMPs (Interface Message Processors) that comprised the ARPANET in 1986. The ARPANET is history now, but thanks to the magic of Pseudo-Scientific Visualization and the ScriptX language and class library from Kaleida Labs, you can now experience what it was like to be free ranging packet hopping around the ARPANET in 1986!
https://www.donhopkins.com/home/catalog/arpanet/index-large....
MIT AI Lab Tourist Policy
https://medium.com/@donhopkins/mit-ai-lab-tourist-policy-f73...
“The MIT machines were a nerd magnet for kids who had access to the ARPANET,”
https://news.ycombinator.com/item?id=15080221
Keith F. Lynch wrote up a fascinatingly detailed and accurate history of the ARPANET from his perspective:
http://keithlynch.net/history.net.html
Keith mentions that ARPANET TACACS passwords were installed in 1986, and even mentions how Jerry Pournelle got himself kicked off the ARPANET for being obnoxious in 1985, which I can conform with the email messages he mentioned. The first message is about TACACS, and explains how MILNET TACACS was implemented in 1984, before ARPANET TACACS (in 1986). It was addressed to the same DEVON, and HN's own GUMBY chimed in with some salty remarks:
https://www.donhopkins.com/home/catalog/text/pourne-smut.htm...