One of the more popular TV ads during the 2010 Super Bowl was sponsored by Audi and takes a poke at the imaginary "green police" out of control.

Standing at the checkout counter of a store, the clerk tells a customer: "Okay, so it's $37.08. Paper or plastic?"

The customer replies, "Plastic."

Into the scene walks a uniformed officer who says, "That's the magic word. Green police. You picked the wrong day to mess with the ecosystem, plastic boy." The officer then hauls the customer away with his hands in cuffs behind his back.

In quick succession we see different scenes of the green police arresting other people guilty of minor environmental infractions.

Green police line the side of a suburban street sifting through garbage cans at the curb. An officer finds a battery in the garbage. An officer in charge yells, "Let's go. Take the house."

A man stands at his kitchen sink at night with an orange rind in hand. Suddenly a searchlight blazes through the window upon him and a green policeman orders over a loudspeaker: "Put the rind down, sir! That's a compost infraction." The man puts the rind down and runs away into the darkness.

A green policeman stands on the brightly lit porch of a comfortable looking suburban home. When the homeowner walks onto the porch, the officer asks, "Did you install these bulbs?" When the homeowner says yeah, he is hauled away to a waiting squad car, and a TV reporter speaks into the camera, "Tragedy strikes tonight where a man has just been arrested for possession of an incandescent light bulb."

A green policeman busts two teenagers for drinking from plastic bottles.

As green policeman surround a man and woman in a hot tub, one of the officers announces, "The water setting is at 105," and the couple is arrested.

The commercial ends with a green policeman busting two real police officers in a squad car. The green policeman asks the real cop, "Are those Styrofoam cups you're drinking from?" The cop says yeah, and the green policeman responds, "Please step out of the car and put 'em on the hood."

In this ad, the problem with the green police is that they are pursuing a good thing—a healthy environment—in an extreme way. They are well meaning, but overzealous.

So it is with legalists. While some are motivated by a Pharisaical spirit, others are pursuing a very good thing—purity and holiness—but they are doing it to an extreme. They police the actions of others in behaviors that the Bible says nothing specifically about. While the Bible does call the leaders of the church to exercise church discipline with regard to certain actions that are clearly named in Scripture, legalists want to raise the bar and also enforce their extra-biblical standards on others.