Comment Incognito/Private Window/etc (Score 1) 112
Then your browser will not give your search agent of much of a chance to track you, and in most cases you have the source code to verify that. Search engines don't bother to track by IP because it's both unreliable and you will likely be pissed off if you see ads which are too relevant when you take such precautions.
Presumably most of your searches are not privacy sensitive and you might even appreciate the ads that show what you are looking for right at the moment. And when you are seriously looking into overthrowing your government, you use your browser's Incognito mode to connect to Tor over a VPN provider outside the jurisdiction of your local spooks.
Use DuckDuckGo if you like it, but it can not be your only privacy measure when you need real privacy, especially as startup on American soil forwarding searches to Putin's Yandex. Most search engines track you to get some money from ad clicks. Having to produce records to various law enforcement agencies is both costly and bad for brand reputation, so some effort is expanded in degrading usefulness of stored data for this purpose while minimally complying with the law.