We also save searches, but again, not in a personally identifiable way, as we do not store IP addresses or unique User agent strings.

DuckDuckGo doesn't save <em>your</em> searches and doesn't send your searches to other sites. No personal information is saved either. No cookies are used by default, but cookies can be saved on your computer for some features (e.g. settings). “We also save searches, but again, not in a personally identifiable way, as we do not store IP addresses or unique User agent strings. We use aggregate, non-personal search data to improve things like misspellings.”