content: Teamviewer connections are not directly peer-to-peer; both users make an outgoing connection to Teamviewer's servers, therefore they can match user IDs to the IP addresses used to connect, and notice that guests from all over the world are accessing (desktop) hosts which did not have that usage pattern previously. Source for claim about connections: I had to use it once, and didn't need to forward a port. Comment: it seems to me that Teamviewer would be able to access images of anyone's desktop.