At present I can see what people are looking at on my sites, how they got there and what they downloaded. Email servers have logs so it's not a leap to think that anything you're doing online right now is not being logged somewhere. Histories tell you where you've been and I'm sure the server can accumulate the same data and measure it's bandwidth requirements.
You can't really be anonymous on the Internet and like the water that runs through your meter you get what you pay for. If everyone filled the swimming pools at the same time there would be a problems with availability. The pipes would be too small, the pressure would be too low, no one would be happy. I don't object to the City knowing how much water I use, I pay for it.
A Time Warner manager, (neighbor) told me that our area is only using 20% of its bandwidth capacity. So for this area Snooping couldn't be justified. Also, by shifting time of use to off peak hours it would impact TV programming and advertising schemes. It would affect work schedules and school performance if the cheapest time to use the Internet were 3-6 am. Many other systems would be affected just so some areas could avoid building the capacity they need to service their customers.