This is the answer. I run a niche social site, and a blank referer from a device that the site doesn’t recognize has become a red flag. It’s almost always a bot or a scraper. The less lazy ones spoof a Google referer, and the sophisticated ones render the page and even simulate human input. It’s a difficult battle even for a smalltime site like mine. I can’t imagine the war that reddit must battle against scraping. I love my privacy, but being as private as possible is going to come with frustration as we get lumped in with the likely bots and scrapers.