I cannot find the report now, years ago an ISP here in the UK did a trial of data mining (I think they used deep packet inspection) and injecting averts on their unsuspecting customers.

When they were caught out they said they decided not to tell their customers as they claimed their customers wouldn't understand. The government and related watchdog did nothing about it. I recall reading that the relevant branch of the EU threatened to sue the UK government if they didn't act. I don't recall what the outcome was.

I believe the trial was conducted by BT Internet and a third party company whose advert related tech they used.

At the time I recall the IT/tech news sources were reporting it as that's where I read about it. I don't know what the general news media reported on the subject.