British Airways settled a class action lawsuit over fuel surcharges. See, these fees had nothing to do with the price of fuel (as required by the Department of Transportation). They awarded cash or miles to a whole bunch of frequent flyers, but continued charging the fees — they just stopped calling them fuel surcharges, and started calling them surcharges. In other words, extra fees that no longer even pretend to have a purpose.
While fuel surcharges aren’t a government tax, they are a tax on frequent flyers, a fee for using miles for free travel (ironic, huh?).