And yes, we can block entire subnets. You own the IP addresses, you're responsible for stuff coming out of them, at least to the degree that it's not maliscious to the web as a whole. (but not the content itself, of course)
I'm calling bullshit on these assumptions. The internet is a communications tool. If it's not communicating, it's broken. If you provide dynamic IPs to clients that attack people, you're breaking it. It's not my problem or something I should ever be expected to pay for.
To be clear, my point is that we're suggesting yet another layer of commercial, paid crap on top of a broken system in order to fix it. It'd be phenomenally better just to publicly identify place and methods where it's broken and let other folks with more vested interests than information consumers worry about it. Hell, I'm not interested in paying for the current busload of bytes I'm currently consuming for every one sentence of value I receive.
One of the things that gets lost in this kind of debate is that the vast, vast majority of Internet users are not experts in how the Internet, computers, or their phones work. So expecting them to be able to "just not get exploited" is a naive strategy and bringing the pain to the ISP feels counterproductive because what, realistically, can they do to stop all of their unsophisticated users from getting themselves exploited?
At the end of the day, the vast majority of the users of the Internet do not care how it works - they want their email, they want their cat videos, and they want to check up on their high school ex on Facebook. How can we rearchitect the Internet to be a) open b) privacy protecting, and c) robust against these kinds of attacks so that the targets of DDOS attacks have better protection than paying a third party and hoping that that third party can protect them?
> We might fix this, we might not, you DONT have a choice.
> Thank you for your continued business.
(swap in any corpo-service provider you personally like the most)
Blanket banning subnet ranges from services because of the actions of someone else is 3rd world shit.