Today's (July 5) Washington Post carries this story about how customers use the Internet to shame large, often indifferent providers on customer service issues. Of note, the first two examples involve Comcast and Time Warner.
One has to ask, absent NN, how well these kinds of customer criticism sites will download? Again, it won't take anything as crude as blocking. Just make it download slower or drop every few times. After all, it's not as if these individual customers can afford to pay for “premium” tier carriage of their material.