If I understand DDG correctly, they use Microsoft Bing as their backend for search results. So while they may be branded DDG, the results are in fact out of DDG’a control. It also means we are more subject to Microsoft’s privacy policy than we are to DDG’s.
This is exactly right. DDG is basically a front end that’s supposed to strip out identifying information and then submit your request to Microsoft. [Edit:] Apparently they have expanded from this, according to their Wikipedia page. [/E]
However, after seeing TV ads for DDG not that long ago I kind of lost what faith I had left in them. As a rule of thumb, I’ve never trusted products and services advertised on TV - TV advertising is expensive, and the business expects to make that expense back and then some from their customers.