http header and proxies

[evolutionator]

I use internet for many things, one of them is downloading files.
The file I download often comes from hosting services.
Said hosting services often don't permit users to download more than one file contemporaneously (except for the ones with bugs or similars).
The solution I used for years is obvious: proxies...
...Until a point when a hosting service told me: "no, you're downloading another file". And I thought: what? How does it know?
So exploring all the possibilities I came to a solution: the proxies where giving my ip to the services, and the way they do it is the field "X-Forwarded-For".
So now my question is: why the **** a proxy should give your ip to others? It's a damn proxy, it's supposed to hide me!
(and i can begin to answer myself, really: because the anonymizing proxies in this way can ask for payments)

[th3g00n]

It seems you're using a transparent proxy. Transparent proxies are just like normal proxies, the only difference is well...it's transparent. Sites you surf to are aware you're using a proxy.

This might help you understand more: http://tools.ietf.org/html/rfc2616

[evolutionator]

It seems you're using a transparent proxy. Transparent proxies are just like normal proxies, the only difference is well...it's transparent. Sites you surf to are aware you're using a proxy.

This might help you understand more: http://tools.ietf.org/html/rfc2616

It has to do a bit with transparent and non-transparent proxies, but the point is x-forwarded-for is an experimental field that did not exist and that still should not be present in a proxy like the ones that are advertised on internet, in the sense: it's ok for a service that act as a proxy to tell other computers the agent is you, IF it's just a service that helps to surf where you can't, but now almost every proxy uses it (whether they're aware of it or not), which means that in internet the whole point of anonymization falls.