I was asked to set up a FORE ATM switch. Initial configuration was done with a terminal hooked up to its serial port; after that, you telnetted to it and used a command line interface called AMI. While it was booting, I saw that it was running SunOS. It's a UNIX system! I know this!

So I booted it single-user and poked around. Found a /.rhosts file with an IP address registered to FORE. (Before ssh came along, passwordless authorization was done by putting a list of IP addresses in your home directory's .rhosts file.) We weren't directly on the Internet, but I saw no need to give anyone passwordless root access, so I deleted that file.