1) Most people are ignorant to the fact that VO is an illegal fuel.
2) The government should have better things to do than to crack down on the tiny insignificant percentage using SVO of the tiny percentage of the population that uses diesel cars/trucks such as blowing our generation's budget on a useless war.
3) They probably recognize that there's no point in shutting down the companies because (a) more will pop up in their place, and (b) people will still break the law themselves.

Feel free to report any violations to the EPA Enforcement Office contact, Jack McLaughlin. Mclaughlin.Jackj@epamail.epa.gov