I have to write a review of a film or play I've seen and I chose "Law Abiding Citizen"

I need help (the theme isn't really a theme, its the plot but I can't really come up with a theme.) Could this be it?

A man seeks revenge on the justice system for not putting the men who murdered his family in prison.

"Law Abiding Citizen"

Directed by F.Gary Gray

Starring: Jamie Foxx and Gerard Butler

Theme: A brilliant man orchestrates a series of high-profile murders that grip the city of Philadelphia - all from inside his jail cell. The prosecutor assigned to his case realizes he is the only one who can end the reign of terror.

This sounds like a theme to the movie. I have seen it and I would have to say that this pretty much sums it up.