Would it not be legal to install a chat script that's just open before and after kick-off so members could discuss pre and post match in a chat forum?
This might be better for the server aswell so it doesn't have to handle all the posts....
In this chatroom some members could "accidentally" post a url that might just be broadcasting a game.
if Sky/Fa came down hard because they saw someone posing a URL in this chat, you could just show them a policy which states members will be banned... and just change the caught offenders username.