Duck Duck Go
Duck Duck Go is a privacy centered search engine. It's home page states "The search engine that doesn't track you". It's Privacy Notice states that it does not "collect or share personal information" (see Duck Duck Go Privacy Notice).
As tracking people would be antithetical to its public position, Duck Duck Go responded forcefully by declaring that it does not collect personal information and that was the victim of a false positive result from the CanvasBlocker Firefox add-on (see TechCrunch link).