you could also say that it's left over fuel you got at a petrol station after hurricaine katrina. I was just talking to a truck driver friend of mine the other day, and he said that stations all over the south had dyed red diesel fuel that was being sold through the regular fuel pumps in the aftermath of katrina. There was no regular diesel to be had. The road tax was payed on all the red fuel sold at those stations, but for a time you could not get in trouble for running the red stuff.
Quis custodiet ipsos custodes (who will watch the watchmen?)