If this violates law, then surely ignoring robots.txt also violates the law. In this case website owners should be able to sue Cyveillance (Comcast outsourced copyright enforcement to them). http://en.wikipedia.org/wiki/Cyveillance
You would want to first take the stop of notifying Cyveillance that you had found they were ignoring your robots.txt and demanding that they stop doing so, or else face legal action. After that, yes, go for it.