Yes, my understanding is that it would be a felony. I can tell you that if I had leaked classified information while I was in the U.S. Navy, I would have been dishonorably discharged and put in prison, something I was made aware of on a fairly regular basis. Not that they needed to worry about me, because I actually took my oath seriously and was determined to follow the law at all times. Sadly, however, people like Clinton, Brennan, Comey, et al. always seem to get away with things the rest of us never could. It's infuriating.