> How do you create the hash? If it's based on something that you can derive from the user (let's say sha1(IP address + User Agent), that seems pretty clearly i

> How do you create the hash? If it's based on something that you can derive from the user (let's say sha1(IP address + User Agent), that seems pretty clearly identifying. of course that is forbidden. and that's exactly why it is really hard to tell if companies honor it.