Before 2015, there was really nothing stopping them from doing it aside from consumer outrage. But as time goes on, large ISPs have been making more and more noise about "internet fast lanes". There have been several incidents of them throttling sites like Netflix in secret. So while they previously adhered to defacto-net-neutrality via informal gentlemen's agreement, the likes of Comcast are no longer acting like gentlemen.
Without net neutrality, it will get worse. Especially since ISPs are also cable and phone companies who are justifiably worried about how the internet is increasingly affecting their cable and phone revenue.
Before 2015, there was really nothing stopping them from doing it aside from consumer outrage. But as time goes on, large ISPs have been making more and more noise about "internet fast lanes". There have been several incidents of them throttling sites like Netflix in secret. So while they previously adhered to defacto-net-neutrality via informal gentlemen's agreement, the likes of Comcast are no longer acting like gentlemen.
Without net neutrality, it will get worse. Especially since ISPs are also cable and phone companies who are justifiably worried about how the internet is increasingly affecting their cable and phone revenue.