Movies
Not up to no good are you? ‘Cause if you are there’s a fifty cent “Up to No Good” tax.
— The Taxman ‧ Popeye

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The question turns a suspicion of mischief into an opportunity to charge a fee. Naming an 'Up to No Good' tax treats wrongdoing as another routine category for collection. The absurd combination of moral disapproval and a precise small price gives the exchange its joke.
Context reviewed