For many rioters who stormed the U.S. Capitol on Jan. 6, self-incriminating messages, photos and videos that they broadcast on social media before, during and after the insurrection are influencing even their criminal sentences. Earlier this month, U.S. District Judge Amy Jackson read aloud some of Russell Peterson’s posts about the riot before she sentenced the Pennsylvania man to 30 days imprisonment. “Overall I had fun lol,” Peterson posted on Facebook. The judge told Peterson that his posts made it “extraordinarily difficult” for her to show him leniency. “The ’lol’ particularly stuck in my craw because, as I hope you’ve...