We've seen cartoonist Bill Watterson's advice transformed into words of inspiration, but this may be the first time one of his strips has been used in a courtroom.

The Rochester, Minnesota, Post Bulletin reports that when it came time last week to give instructions to a jury considering the case of 20 silica sand protesters charged with trespassing, Winona County Judge Jeffrey Thompson turned to a classic Calvin and Hobbes comic.

The strip (above), which debuted on Nov. 28, 1992, features Calvin wondering why superheroes tend to fight villains set on destroying the world instead of more realistic threats. When Hobbes points out that the hero could attend council meetings or pen letters to the editor, Calvin discovers the answer.

According to the newspaper, Thompson encouraged the protesters to attempt to change minds about frac sand mining through regulatory channels, like the city council or the county board. When defense attorney Richmond McCluer asked whether the Calvin and Hobbes strip would be entered into the record, the judge handed it to his clerk with "a wry smile":

"Perhaps a first?" McCluer quipped.

"Perhaps," Judge Thompson responded as a crowd of 30 laughed.