Teach a Man to Fish or Give a Man a Hammer
You know that metaphor about the man with the hammer? That, from his perspective, everything looks like a nail? The same could be said about prosecutors and overly broad criminal laws. In the most recent example, federal prosecutors used the Sarbanes-Oxley act, a criminal law created to give prosecutors a weapon against bad companies like Enron, to prosecute a grouper fisherman. For allegedly throwing some under-size fish overboard.
The problem with criminalizing more and more things is that we just end up giving overzealous prosecutors more and more hammers. The prosecutor has a duty to “do justice,” not to try and convict as many people as possible. Prosecutorial discretion (the ability to drop cases that can’t be proven or that the prosecutor believes shouldn’t be proven) plays a big part in that duty. But, the more hammers we give to prosecutors, the easier it is for them to forget what their duties are.