Hey entarpe, my point about 50% of those working proxies in your list being CoDeeN/Planetlab proxies has nothing to do with anyone's ability to crack porn sites with them ... least of all mind.
Most people who have need of using a proxy, wish to do more than simply surf with it. They want to login to various sites, post messages, check email, etc., and with CoDeeN/Planetlab proxies they cannot.