My understanding is that google is having a legal dispute with the government because they asked google to surrender a list of the sarch terms by the users and all the info regarding users such as IP's and stuff. Google is refusing so the legal battle has just begun. It's likely that they are looking for terrorist threats, but I wouldn't disregard drug smugglers/dealers. Since AAS are considered just as bad as cocaine and weed, then make you conclusions yourself.
No matter what you hear or no matter what people say there is no way to stay 100% anonymous on the internet. You can certainly make things harder for the DEA or the FBI, and try to conceal your IP address, clean your internet traces off your PC, but there is always a way to get the internet traces back to your door.
After so much struggle with proxys servers and anonymous internet software, i gave up and to stay as private as possible by going to the library or any place where they have public internet access and do my browsing there...this way the IP address can't be linked to my personal info such as address/name, and my privacy relies on myself and not in bogus proxy servers or internet software, or people/organizations that claim that is going to defend my privacy. Don't forget to smile when on candid camera though!!!.
There is no such thing as privacy as far as i'm concerned...not in the U.S.