was fällt Ihnen ein

what do you think you're doing?

→ was
phrase Rare #41,729
what do you think you're doing? Used to express indignation or disapproval. Literally, it means “what occurs to you?”
GE: Was fällt Ihnen ein, mich so anzuschreien?
EN: What do you think you're doing, shouting at me like that?

Was fällt Ihnen ein, so über Tom zu reden?

How dare you talk about Tom like that?

Was fällt Ihnen ein!

What are you thinking!

— Fahrraddiebe (1948)

Was fällt Ihnen ein, so was zu sagen?

What makes you think you can say something like that?

— Catch Me If You Can (2002)

Was fällt Ihnen ein?

What comes to mind?

— Das Experiment (2001)

Was fällt Ihnen ein, Sie verdammter Vollidiot?

What do you think you're doing, you damn idiot?

— I Saw the Devil (2010)