Recs.
Updated
DuckDuckGo is a competing search engine to Google that focuses on increasing search productivity while protecting user privacy.
SpecsUpdate
Pros
Pro Very protective of user privacy
DuckDuckGo does not collect or share any personal information. Their privacy page has a great rundown on why privacy is important. The most important repercussion of this is that DDG doesn't use the data collected to tailor results, avoiding exposure to the "Filter Bubble".
Cons
Con Bangs do not protect user privacy and can be misleading
Using these bangs will instantly connect you to the service you requested. For example typing “!g white cat with green eyes” and hitting return, drops you off on the Google website to display your results (thus logging your IP, search term and browser info immediately). It does not get you Google results inside DuckDuckGo. It is reasonable for DDG users to assume and expect a private search engine warns if there is a risk to that privacy being lost, like it does with Youtube videos but in the case of Bangs this does not happen.
Con Referrers
A referrer is an HTTP header field that identifies the address of the webpage (i.e. the URI or IRI) that linked to the resource being requested. By checking the referrer, the new webpage can see where the request originated.” Basically it tells a website where you came from. DDG does give this out.