A friend of mine ran a long tail content generation service, much like HitTail, and recently had all his clients penalized regardless of the quality of the content they wrote for those long tail keywords.
Apparently they already anticipated something like this because several other companies were being manually penalized over the past year and half following an algorithm that seemed like: "Which big AdWords spenders cut down significantly on their budget? Are they getting it organically now? Let's cut that off."
Several of those companies are suing Google for violating EU regulations, so hopefully something will come out of that.
The first step will probably be that penalizations can be fought through the EU judicial system, but it will be a while before we get jurisprudence on that.
I don't know how this would work in the US legal system but, regardless of what the outcome would be in Rap Genius' case, it's probably time for similar jurisprudence to be established in the US.