List of trusted proxies?

proxies of provider who do pass along the client's IP

[janharders]

Hey everbody,

does anyone know about a list of proxies that transmit the client's IP _and_ can be trusted?
It's for IP-bases throttling / banning. If I use my providers proxy, it'll pass along my IP. In that case, my script should use the IP specified in HTTP_X_FORWARDED_FOR (or any other of the possible headers) to calculate wether the amount of data downloaded is ok. But, if the request supposedly comes from a proxy, telling me the originating IP, I cannot be sure that it's really a proxy, not just a client in disguise, so the information about the original IP cannot be trusted.
On the other hand, you don't want to block a provider's proxy, since that might include quite a lot of people.

tl; dr
a list of non-anonmyous, closed proxies that can be trusted to provide the real IP.

thanks

[janharders]

does nobody know of anything like this or am I the only one who thinks it'd be a good idea?