John McCain has endorsed the misnamed “Free Flow of Information Act,” otherwise known as the “shield law” for journalists, which would confer special privileges on the Fourth Estate, including immunity from being forced by a court to reveal sources. It’s a bad piece of legislation and McCain is unwise to support it, though it has won him plaudits from the usual media suspects. Both the Democratic hopefuls support the bill, too.

The problems with shield laws are many. First, this is a law designed to make it easier, or even consequence-free, to break other laws. The bill should be called the “Free Flow of Classified Information Act.” It is illegal to disclose classified information. If you believe, as I do, that the government is promiscuous in its use of classification, and that much less information should be made secret, then you should support legislation to that end. Protecting those who break the law from the consequences of breaking the law is a very poor substitute for reforming laws that beg to be reformed.

But the most dangerous part of the shield law is that, at some point, either a judge or a federal functionary will be forced to make a determination about whom the law covers. Which is to say, there will be a federal determination of who counts as a legal journalist and who doesn’t. This amounts to having the federal government license journalists, which is undesirable on many levels, and which will certainly have First Amendment implications. The many uses of this sort of classification tend to get way out of hand very quickly, which is why things like an ID number for the government pension program and state permits to drive end up being entangled in so many areas of life that have nothing to do with pensions or driving. Try getting through a year without using your Social Security Number or your driver’s license. Many on the Left already believe that the Second Amendment should be restricted to state-authorized guardsmen. How long will it take for like-minded authoritarians to argue that the First Amendment’s free-press guarantees only apply to government-recognized journalists?