You cannot be anonymous on the internet. Just accept the fact and get over it !
(1) Your ISP is governed by the regulatory environment, if the Police ask them to cough up information then they will.
(2) Disgruntled/Insider engineers working for your ISP could see your traffic flows if they wanted to (even though this would be illegal with no suitable justification).
(3) Even if you use a third party service such as "Anonymiser" .... they are still subject to a/ the regulatory environment ... i.e. Police wanting to track you down, and b/ how do you know they are not watching you ?
Basically, if you've got nothing to hide, you've nothing to worry about.
Actually, there is one way you can be anonymous. Go to an internet café, but make sure it's one where you can pay in cash, there are no CCTV cameras and hope that the guy behind the counter is dumb enough not to remember your face, oh, and you had better find a lot of them, because you don't want to go back to the same one twice. That's anonymous, or at least it is until the forensics officers track you down ...
There is no privacy in this world. Tell me, how do you anonymise your phonecalls ..... the withold number feature is worthless you know !