T-Mobile has that set up in the US. Luckily you can at least opt out, which I have. T-Mobile offers various unmetered streams if you use the apps, but they degrade the quality of the stream. I believe all youtube streams become 480p, for example. I don't trust that they don't or won't affect other sites in some negative way.

Frankly, I'm happy with the data plan I have and I have no need to bargain off portions of the internet so that my ISP can closely monitor and manipulate certain sources.