Surfing in the dark
If you are using free proxies to hide your tracks on the Internet, you might consider if that’s a good idea.
I found this article the other day by Christian Haschek, which is quite interesting: Why are free proxies free?
The article describes how proxies can be used to manipulate Javascript files you are downloading when surfing the internet, and use it to monitor whatever you are doing on the web. And even how to configure Squid Proxy to manipulate with the .js files – which is pretty easy.
So next time you consider to use a free proxy, keep that in mind, that you might let someone watch what your are doing, and remember to clean your cache/cookies afterwards 🙂