[ykaranfil]

I don't know if this is normal? I followed the tutorial on fixtracking.com and installed DuckDuckGo plug-in for Firefox, and later i realized by analyzing http traffic that everything i type in address bar is sent to DuckDuckGo, even it is not selected as a default search engine. I wouldn't trust DuckDuckGo

[crazedpsyc]

There is nothing malicious going on there. It does that so you can get instant answers where there would normally be auto-completion. This is covered very nicely in a paragraph in the addon's description, and can very obviously be disabled in the addon's preferences.

[ykaranfil]

If you check the chrome page on fixtracking.com (prepared by DuckDuckGo), it is asking you to uncheck "Use a prediction service to help complete searches and URLs typed in the address bar", so what is the point here?It is enabled by default.

[crazedpsyc]

Not sure what you mean there -- these are two completely different things. That disables using a service (Google or Bing) to autocomplete. It does not affect what extensions like the DuckDuckGo one do.