I use the Pentadactyl Firefox extension, which lets me control Firefox from the keyboard (in much the same way as vim), so websites which try to inject their own keyboard shortcuts really get my goat.
DDG does this too. But fortunately, there's an easy way to turn it off in the preferences.
Unfortunately, there's a problem with setting preferences on DDG (or any other websites), as your preference choices can be used to track you.
I love the keyboard functionality google has.