Online Lobby

I can suggest a rather simple method for detecting open-map cheating, as well as a couple of telltale signs that a player might be doing it. I say this because I was surprised to learn how one can play with an open map, and I immediately wrote to Baratortch and Dirty about it. Unfortunately, this method only works with software assistance; if the opponent isn't streaming their game, it's not possible.
I don't want to reveal any specifics here, but I can share my limited experience and thoughts on this issue to help eliminate and detect unsportsmanlike behavior.
Another, simpler option is to simply avoid playing against those who are clearly suspected of cheating, but then this ambiguity and lack of proof can be particularly irritating, especially for those who are already prone to getting upset.