Likely nobody would even realize. It's not like the telcos would block sites. Instead, suddenly Netflix loads a lot slower than Comcast. Blame Netflix and move on.
Netflix might have the clout to do so, but a small startup which nobody has heard of never would.
Ultimately, the consumer mindset is never to blame their provider. They blame the website. If you come to my site and it's throttled, there's a high chance you'll click away and never come back.
thats generally how that stuff starts to be tolerated. "it wont fly so i don't care".
then since there is a HUGE financial interest, they try again, and again and again, and nobody's to block them, it eventually works.
Bad news for old money - the Internet has an appetite for rentier blood. This will not be tolerated long term.