John Stossel‘s latest column at Human Events focuses on a case from Wisconsin that should concern any advocate of free speech.

Modern campaign rules are so complex no one is certain what is legal. Yet one misstep is enough to get accused not just of bad political arguments, but also of “collusion” and racketeering. Raise money for a cause you believe in and get close to politicians you favor, and you may be accused of funneling illicit money to their campaigns.

In Wisconsin, prosecutors may also impose what’s called the “John Doe” rule: Don’t tell anyone that you’re being investigated, not even your kids, your spouse and definitely not the media.

Prosecutors claim secrecy is needed to “protect privacy” of people under investigation — if charges are dropped, no one need know that you had been accused. But in truth, says Eric O’Keefe, another limited-government activist who Wisconsin prosecutors investigated, “This is about shutting us up. That’s all it is. It is a speech suppression play.”

It’s also a way for political insiders to punish their opponents. O’Keefe is a Republican, and the lead prosecutor, Milwaukee District Attorney John Chisholm, is a Democrat, but two Republican insiders signed off on the raids, too. “I take cold comfort in having my constitutional rights trampled by both parties,” says O’Keefe.