You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
You will be given a passage, and your task is to generate a Yes/No question that is answerable based on the given passage.

Powdered sugar, also called confectioners' sugar, icing sugar, and icing cake, is a finely ground sugar produced by milling granulated sugar into a powdered state. It usually contains a small amount of anti-caking agent to prevent clumping and improve flow. Although most often produced in a factory, powdered sugar can also be made by processing ordinary granulated sugar in a coffee grinder, or by crushing it by hand in a mortar and pestle.
Solution: is confectionary sugar the same as powdered sugar?
Why? The question is a yes/no question, and it is answerable based on the given passage.

New input: In the United States, although the legality of headlight flashing varies from state to state, a federal court ruled that flashing headlights was a constitutionally protected form of speech, issuing an injunction prohibiting a police department from citing or prosecuting drivers who flash their lights to warn of radar and speed traps.
Solution:
is it illegal to flash lights to warn of police?