And what would prevent them from running port 80 and 443 cross-domain p2p ? If I remember correctly, kazaa had a mode that worked like this. Suppose you'd do i

And what would prevent them from running port 80 and 443 cross-domain p2p ? If I remember correctly, kazaa had a mode that worked like this. Suppose you'd do it really, really simple. If you watch a netflix show, you download an encrypted version, and start serving it on your IP address on ports 80 and 443, http and https (wouldn't work with NAT of course, but ...). Then inform central servers that this link exists and the central server tells 1/10000 of next requests to download it from you. Now split up the files into 1000 pieces each, and make it work like that. It could take care of tracerouting to everyone and try to "group" requests with the most overlapping traceroutes. Bittorrent is a brutally simple protocol, compared to it's predecessors, and I'd say, even compared to things like http and https. Running bittorrent over http or https would not be very hard. Keep in mind that there's also an advantage for the providers. What the providers really want is payment for building network infrastructure. Given how hard that is becoming, and the fact that it's not linear (for linearly increasing endpoints and bandwidth you need exponentially increasing network equipment and transfer lines), they should be ecstatic about efforts to turn traffic back as soon in their network as possible, it would offload their core networks, and they can sure use that. Contrary to what people think here, in most cases ISPs only throttle p2p traffic either between their distribution and core layers, or between their core and peering (second makes more sense financially, but it may not be the same organization). So p2p traffic between you and your neighbor is not throttled at all. This is done because firewalls that can reliably separate p2p traffic from other traffic are expensive, so one tries to avoid sending all core traffic through them. Throttling p2p in the access servers is quite expensive, and will give customers (even more) the impression that their line is throttled at all times. (also in most ISPs even a basic business connection will bypass p2p throttles, given that the cost difference between customer connections and basic business connections is little or nonexistent these days, you may want to consider switching)