Chicago based Cshel has a nice post on Google index spam in regards to metal buildings. I agree with her as I see this type of spam in my akismet comments coming from .edu domains which have obviously been hacked or compromised.
This must have been a ton of work to research and is worthy of wide attention to this significant problem! It will be interesting to see how Google responds if at all.
It also reminds me of a recent post I did regarding the relvancy of Ahmed.