It's true that gun-free school zones can't stop "bad guys" from bringing guns to schools with the intention of hurting people. It's true that somebody who's prepared to commit murder won't worry about offending a lesser statute. However, what gun-free school zones do prevent is people bringing guns to schools for supposedly "good" reasons, and then accidentally or recklessly causing harm. This is an important protection! Let's be realistic: Even though the news is filled with stories of dramatic mass-murders, the majority of gun-related deaths and injuries are made up of accidents, friendly fire, and suicides. If we want to protect children from harm, we can't just protect them from "bad guys." We also need to protect them from the negligent or reckless mistakes of otherwise "good" people.