This is an interesting problem. On a broadcast channel, when a local station attempts to replace the ads the network has put in their shows, with their own ads, the network has some leverage to shut down that process. But on the Internet there are a bunch of web sites and they don't have any leverage at all. They could do an IP filter, which is to say put up a page "This site unavailable on this ISP's network" when a…
They could use TLS...