Should duplicate HN submissions have names of all submitters?

Better yet. Stop any repeat submissions of the same article for at least four days.

"Sorry. That article has been submitted already."

Time and time again we get the same article submitted by half a dozen (or more) submitters over the course of several days. ONCE is plenty.

Won't that encourage duplicate submissions? The current approach seems "good enough".

Would be simple to implement using the API