One tradition of the show of course is how NICE most of them are, like Shirley Blaine. Which is entertaining (although I've always thought the first blackmail scene between Tanner and Nick and Lily sort of overdid it).
It seems like nearly the only times a blackmailer is arrogant about it is when it turns out to be a TRICK, as with Artie in A FRIEND IN DEED and Margaret in RANSOM FOR A DEAD MAN.