One example I can remember:
I was working on some linux V4L2 code and wanted to get more informations on the "buf_queue". By mistake I searched for "vbuf_queue". Google's results:
https://encrypted.google.com/search?q=vbuf_queue
It only shows 3 results where I am (and 0 a few months ago when the problem occured) which makes it pretty obvious I'm not searching for the right thing.
As for DDG:
https://duckduckgo.com/?q=vbuf_queue
It displays a pageful of garbage that I will parse for a while until it occurs to me I made a typo.
And it does it for pretty much any bogus query as well, compare:
https://encrypted.google.com/search?q=aoeulcrnh34ui345u34iyi...
with:
https://duckduckgo.com/?q=aoeulcrnh34ui345u34iyi3euieuiaeoua...
In this case ddg happily outputs what appears to be misinterpreted binary files.
Maybe DDG works well for non-technical contents but 90% of my queries at work are obscure programming/electronics stuff, component datasheets and the like. For that ddg is simply not usable by my standards.