> Query strings are probably the least invasive tracking. They are transparent, obvious, and anonymous. They're not necessarily anonymous. utm=Google.com is, b

> Query strings are probably the least invasive tracking. They are transparent, obvious, and anonymous. They're not necessarily anonymous. utm=Google.com is, but s=abcdefg, where abcdefg is a hash of the specific user that generated that link, identifies to the site the specific user the link was shared from.