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.

United Airlines and Delta Air Lines were hit with class-action lawsuits Tuesday accusing them of charging passengers more for “window seats” that were actually next to an opaque wall. Law firm Greenbaum Olbrantz filed the cases in federal court in San Francisco and Brooklyn,