Personally I think the DOJ should investigate refineries, as none of the seem particularly eager to compete on price. They're making record profits as the price of crude collapses while the price of gasoline is flat.
http://www.latimes.com/business/la-fi-refinery-profits-recor...
It seems very fishy to me that we have so much crude building up, yet consumers aren't seeing any real benefit from cheaper gas, cheaper shipping, or cheaper domestic flights.