Den 10 feb 2015 11:48 skrev "MⒶrtin HⒶboⓋštiak" <martin.habovstiak@gmail.com>:
>
> I still don't understand. The website can have this information
> available. This is exactly what e-bay does - it displays shipping
> information to my country before I do anything. What's the problem?
>
> Also with other stuff, website can do it and browser extension can do
> it too without messing with Bitcoin.

1: IP isn't guaranteed to work correctly both because you might be using a VPN out Tor.

2: Yes, the site can display all options right away, but are you willing to read all of them too?

3: Detailed information is not necessary, nor does it have to be unprompted. It doesn't need to tell you more than which country you are in. It can even prompt you with a popup that has a slider that shows exactly how much information and of what kind you're about to share (including none, if that's your choice).

4: It doesn't need to share raw data. Take a look at anonymous credentials:
http://www.zurich.ibm.com/idemix/
https://eprint.iacr.org/2013/622.pdf

5: It can wait for prompting until you add the first item to the cart.