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.

Some passengers feel more comfortable flying with a window seat, and, as every traveler knows, you can sometimes pay more to ensure you get one. However, a law firm is alleging that some airlines, such as Delta and United,