Every SSL certificate is publicly logged(you can see these logs e. g. under crt.sh) and you might be able to read DNS records to find new (sub)domains. The modern internet is too focused on being discoverable and transparent to make hiding an entire service(domain + servers) feasible. But things like example.com/dhusvsuahavag8wjwhsusiajaosbsh are entirely unfindable as long as they are not linked to

Please put an NSFW tag on this. I was on the train and when I saw this I had to start furiously masturbating. Everyone else gave me strange looks and were saying things like “what the fuck” and “call the police”. I dropped my phone and everyone around me saw this image. Now there is a whole train of men masturbating together at this one image. This is all your fault, you could have prevented this if you had just tagged this post NSFW.