DuckDuckGo has always been big about privacy and that is exactly how it has pushed its browser's agenda ahead in comparison to Google's Chrome, Microsoft Edge and others. Things were going pretty good for the company until a recent revelation by security researcher Zack Edwards.
Edwards has revealed earlier this week that DuckDuckGo's mobile browser allows some Microsoft sites to bypass its tracker block. An exception was made for Microsoft, while the browser was blocking trackers from Facebook and Google. Edwards also found that DuckDuckGo allows data to be sent to LinkedIn and Bing, both domains owned by Microsoft.
DuckDuckGo responded to this by saying that the exemption is because it has a search agreement with Microsoft. Gabriel Weinberg, CEO and founder of DuckDuckGo, responded to the uproar on Twitter and Reddit that followed this revelation.
We block third-party trackers for non-search tracker blocking in our browser. We can't do more Microsoft properties because of our Microsoft search syndication agreement. Weinberg said that we have been pushing and expect to be doing more soon.
DuckDuckGo has added a note about tracker blocking on the App Store description - While we block all cross-site 3rd party cookies on other sites, we can't block all hidden tracking scripts on non-DuckDuckGo sites for a variety of reasons, including new scripts that make parts of the page unusable, and some we are prevented from blocking due to contractual restrictions with Microsoft. Some users are quite uncomfortable with it, and some of them accept it as it stands. Allowing tracking by one particular company, whether there is a deal or not, does not bode well for a privacy-focused browser.