It would be enforced by one player reporting the other for chatting about a rated game in progress. If it were between two players who were conspiring to do well in a tournament, it would be nearly impossible to tell. I don't know if it's possible for others to go through someone's archive and see chat between the players.
I can tell you that it's common for people to post an ongoing game in the forums and ask for advice. Usually it appears that the poster doesn't know the rules and removes the game as soon as they realize they are violating the ToS.
How is your privacy violated? The games are played on chess.com's servers and you choose to play knowing that others can see them. I'm sure you fixed all of these terrible issues on your chess site. What's it called again?
Discussing a game with the opponent during the game is a violation of site rules, unless the game is unrated. Discussion of possible engine use in the main forums is also against site rules
That doesn't make any sense to me. The only reason I play chess is for the interaction. There would be no point in playing the game if you couldn't talk with the person you are playing against. Imagine playing monopoly or sorry and not talking to the people you are playing against. It would be so boring you wouldn't want to play. It seems like any competition or game you are allowed to talk to teammates or opponents.
Agreed, this site is completely OCD about it's rules. Same for these forums which are moderated like the CIA. Let's not forget how this site violates our privacy by displaying ALL of our games in a public domain for everyone to see.