Fortunately they haven't done this for 2 years. They killed it when they flipped on DNSSEC because the practice of NXDOMAIN hijacking is incompatible:

http://dns.comcast.net/index.php/help#faq2

Now no customers from Comcast suffer this.

... JavaScript and HTML injection when you reach a cap limit in a throttled market or when you get a cease and desist for pirating, however, is another matter.