Normative Signs: The Poetry of "Ought"

This sign was spotted posted on a wall-mounted (built-in) trash receptacle in a restroom at CMH (Columbus, OH airport).

The pic was submitted by Phil Smith III, who wonders whether CMH really has just one employee (as implied by the grammar of the sign). Phil also noted that this sign might usefully have directed readers to the “sharps” receptacle located at the other end of the room. Surely the injunction against putting needles in the trash would be more effective if users were told that they had another, safer, alternative.