In the 1980's, the New York State Police visited the local police department in the town I lived because of some dialup mischief I caused. The local police chief toldd them he'd handle it.
The lesson I learned was to do a better job of covering my tracks. But I stayed away from that mainframe after that.
The things many of us did to learn about computers back then would get someone prison time today.
A couple of takeaways:
a. Credit Suisse did not have a username / password to log in. They were using "security by obscurity" in 1980.
b. The local FBI guys in Dallas didn't know you could purchase a modem for a couple hundred bux and hook it up to a $1000 personal computer. They seemed truly surprised to discover I wasn't part of a well-funded white collar crime syndicate and just a kid in jr. high school whose parents eventually gave in when I begged for a modem for a couple months.
c. You can apparently do damage to your reputation at 300 baud.