I got my TI-99/4 confiscated by law enforcement when, after watching War Games, I wrote a script to "war dial" connection strings on the local Tymnet POP. Turns out one of the systems I connected to was the backend clearing system for Credit Suisse. They were neither happy nor had a sense of humor. After logs showed I didn't try to steal money or do anything damaging I got my computer back in a couple of weeks.
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.