Where people used ANSI bombs and did ANSI codes that would lock up browsers. I recall that some people put in "{Control-D}INIT HELLO" in their messages so that it would format the current drive on Apple // systems. I remember using some PETASCII codes that would mess up ATASCII terminals and I had to quit doing that.

I also remember a few *sshole co-sysops that changed my default settings to black text on a black background for ANSI. They did this because they didn't agree with me on debate topics, and that was a way they could get me to shut up. Changing to a different terminal mode, and then entering the BBS User setup screen allowed me to change it back. I was smarter than the average co-sysop back then. :)