10 years or so ago, this happened:

Me: I'm going to disable telnet on all the servers and use ssh everywhere.

Users: Can't do that, our client software doesn't support it.

Me: Oh, what software are you using?

Users: Something called putty.

Me: ...

A quick walk round the office to reset everyone's putty back to defaults and telnet was very quickly disabled.

0

If you have a fediverse account, you can quote this note from your own instance. Search https://mastodon.illumos.cafe/users/ptribble/statuses/115932837069833621 on your instance and quote it. (Note that quoting is not supported in Mastodon.)