Lawyers for William Faulkner’s literary estate have been busy. A day after suing Sony over a line in Woody Allen’s Midnight in Paris film — adapted, they claim, from Faulkner’s Requiem for a Nun — they’ve filed suit against defense contractor Northrop Grumman over the company’s new full-page ad in the Washington Post. (The paper’s parent company is also named in the lawsuit.) The ad in question, which was a celebration of Independence Day, included the line, “We must be free not because we claim freedom, but because we practice it.†Though the ad did attribute the quote to a 1956 essay Faulkner wrote for Harper’s magazine, his estate says its presence in the ad was commercial appropriation, and therefore not fair use.