I may know one of the culprits -- whom I will leave unnamed here. But the company, who is fairly popular, built out their own CDN via putting a bunch of nginx caching proxies on various Hetzner servers around the world. It apparently was really cheap and very effective. Given that they were bootstrapped and this was prior to Cloudflare really being that popular, it was a great strategy. This was true like 8 years ago, so maybe it has changed in the meantime.