When I was about 11 or 12 years old, I was chatting with a friend on AOL Instant Messenger and suddenly was forced into a black screen with green text where I communicated briefly to someone who was forcing this new chat session onto me. The crack scared the absolute crap out of me. It ended once I told the person that I was irritated and that I was going to contact the police (I didn't and I doubt there was anything that really could have been done). Once the fear subsided I became more interested in how this person did what they did. It's one of those weird technology-related moments that sticks out in my mind to this day more than 10 years later.