Commenters across the political spectrum have noted that the Democratic Party's proposals to ban gun sales from individuals on the "no-fly list" raise major due-process concerns; the system by which individuals are put onto the list is notoriously opaque and unreliable. In fact, it turns out that Rep. John Lewis—who led the gun-legislation sit-in on the floor of the House of Representatives that just ended—once announced publicly that he'd been subjected to considerable inconvenience when he was mistakenly put on the no-fly list. From a 2004 CNN article:
A second prominent lawmaker said Friday that he's been subjected to extra security at airports because his name appears on a list designed to prevent terrorists from boarding planes.
Rep. John Lewis, D - Georgia, a nine-term congressman famous for his civil rights work with the Rev. Martin Luther King Jr., has been stopped 35 to 40 times over the past year, his office said.
Lewis' office said at the time that his name had remained on the list ever after he contacted multiple federal agencies about the mistake. (The other prominent lawmaker alluded to in the CNN article, by the way, was Ted Kennedy.)
As you can sort of see above, Lewis and other House Democrats actually spoke during the sit-in in front of a sign which featured a #NoFlyNoBuy slogan. (The image is taken from Periscope; C-SPAN's cameras are turned off since the protest wasn't an actual session of House business.)