The code that runs the World Wide Web was still being written when attorney Mike Godwin came up with a simple law: Sooner or later in any online argument, someone will bring up Hitler.

Today, the 1990 adage known as Godwin's Law seems more appropriate than ever, as social media has turned civil discourse into a never-ending series of flame wars.

But Godwin, 60, who now serves as a senior fellow at the R Street Institute in Washington, D.C., says that's an inevitable consequence of free speech. He'd prefer it if people would stop and think before bringing up World War II analogies, but he's not against it in every single case.

In fact, Godwin recently weighed in when a journalist clapped back at white nationalist Richard Spencer online.