People have cell phones in their pockets 24/7. Someone could demand photographic proof of your ballot regardless of mail in or voting booth. Sure you could doct

People have cell phones in their pockets 24/7. Someone could demand photographic proof of your ballot regardless of mail in or voting booth. Sure you could doctor the photo, but you can doctor paper too. Neither are such common skill sets that there's a real difference between mail in and a booth.