Earlier quoted context omitted.
Not yegg, but if you store a database of queries, along with frequencies, you can do a prefix match on what's already in the search box and return that. I'm speculating that DDG does something that. It doesn't take any PII to do that unless the query itself includes PII. E.g., "websites operated by paul nathan" is pretty PII. :)
Saving - and now seemingly publishing - search queries is saving and publishing PII. http://donttrack.us directly acknowledges that search queries can be used to personally identify individuals. I therefore understood from the later statement on that site, "[ddg doesn't] store any personal information at all", that this would include search queries: ddg almost literally advertises itself on the fact that it doesn't s…
But I want to point out that doing a standard ddg search gives me `https://duckduckgo.com/?q=seattle` , which is a GET command, visible across the entire network as it percolates through, unencrypted.