One reason I like answering to the pseudonym "Don't be doing that!", is that this statement is (nearly) universally known, (among most English-speaking humans), dating, I suppose, from their earliest years.

The biggest reason I like the phrase "Don't be doing that!" is that it is the punch line to a famous joke that probably dates back to Vaudeville.

Patient: " Doctor, it hurts when I do that!"

Doctor: "Don't be doing that!"

                                - Dobe Doinat