[amluto]

I should clarify what I mean: if you have a login page (form element of type login, perhaps), you get a real login button with trusted chrome (i.e. you can't restyle it to look like a kitten). If you push it, the website gets your TLS Channel ID or similar. This isn't a global identification -- it just lets the site match you up to the last time you went there. But the browser could give you an alternative that gives you a fresh transient identity.