I must be overlooking something, but I'm not seeing if game wikis are all public. Is there a way to restrict it to only players in your game?

Never used one yet, but ISTR from chat when they were first made available that, yes, they are public, and no, you can't make them private for your game.

No doubt someone will be along shortly to confirm or refute that... ;)

Yes they are, and no you can't. However, accessing a game's wiki would require someone to know the game's ID number (or guess it). If someone can find a link to a game you're running, they can input the ID to get to the front page of the wiki.

They just need to find the game, the link to the game wiki is always there in the right corner when there is one.

Ok, thanks.

So I suppose a GM (and the players) ought to be somewhat careful about what they post on the wiki so that it doesn't violate the Adult policy, or expose proprietary or copyright sensitive material.

Look like it :)