Hi all
First I should say if you want to test the anonymity of proxies,I think the most
powerfull program is AccessDiver:
hxxp://www.accessdiver.com/
Note:This program is full of adwares but it worth to use.
In addtion,In a group of sites,you can't use anonymous proxies to access them
and you should use tunneling to use them.
sincerely yours