Back in the early 90s the local university used to have a free dial-up that you'd connect to via modem and then could telnet anywhere. You didn't need to be a student or anything. As a teenager I used this to connect to various shell accounts I had around, and to various MUDs. (This was in the pre-ISP days -- there was nobody in my area offering dial-up Internet at all.)
At some point they pulled this and made it for students only. But they had a dial-up gopher service for campus information and library access that was actually a telnet session to a gopher client on a SunOS machine somewhere.
But they didn't disable the telnet escape character.
So for a few months back then the way I got Internet access was to dial into the gopher client, hit ^], close the session to the gopher client, and open to anywhere else I chose. Eventually they closed this hole, too, but it was glorious for a while.