Delta Air Lines and United Airlines have been sued by passengers who claim they were charged extra for a window seat but found themselves sitting next to a blank wall. The lawsuits, filed separately against the US carriers, seek millions of dollars in damages for more than a million customers of each airline.

A new complaint filed against United and Delta Airlines on Aug. 19 accuse the airlines of deceptive business practices and false advertising.

A pair of lawsuits claim passengers were charged more for "window seats," only to find they weren't next to a window at all.