Two weeks ago, a unanimous Supreme Court rebuffed the Securities and Exchange Commission Gabelli v. SEC. The SEC maintained that its enforcement actions for fines under the Investment Advisers Act weren't subject to the five-year statute of limitations. This wasn't the first time the courts have pushed back a federal agency for overreaching. It won't be the last. But the SEC's audacity prompts a broader policy question: What good is accomplished by imposing monetary penalties on corporations, as the agency attempted to do in Gabelli? The answer is that when such penalties are sought by the government, they probably do...