As a network engineer, this is part of why I tell junior neteng and NOC staff that there is definitely such as thing as ethics in network engineering. And train them on what constitutes ethical vs unethical behavior on the part of an ISP.

I'm fortunate enough to have admin rights over the infrastructure of a small to medium sized regional player, where the senior management are principled individuals who would not even contemplate doing bullshit like hijacking http or DNS traffic.

ISPs injecting ads sounds like a wish to manipulate

https://arstechnica.com/tech-policy/2014/09/why-comcasts-jav...