There was a small netcafe nearby when I was young that had a good quality T1 connection and hosted their own CS servers. Some of the players got together and actually mapped out the entire netcafe store itself and some of the surrounding area to create a "de_" style map.
This meant you could be playing CS and spawn in the same room that you were actually sitting in.
I can still remember vividly as a 14 year old playing the game and completely dominating a room full of 20-something older guys in the other room. They didn't know who I was and every time I would stomp them they would yell "FUCK" from the other room. Eventually after a series of absurd kills they angrily stormed over to our room in a hostile manner ready to fight and 100% convinced I was somehow cheating. The look on their face when they realized they were "prepared" to fight a kid and the realization as I openly allowed them to inspect the PC for whatever they thought was modified on it was hilarious.