We’re still taking about Korean ISP charging streaming company for bandwidth, right? If the streaming service setup some TURN servers to help people behind cgnat, then they’ll going to get charged by the ISP because the traffic originate from TURN servers operated by the streaming service instead of peer-to-peer traffics among users. These ISPs rejected Netflix offers to put their caching servers inside their network afterall, so the TURN servers will have to be located outside their network and thus subject to the bandwidth charge.