I’m reading Geert Mak’s Amsterdam (which has nice detailed maps of the city as it was c. 1300, 1575, 1650, and 1980—there’s nothing I like better than a good historical city map), and I ran across the following passage (on p. 78):
For a good deal of the fifteenth century the rest of the Low Countries was plagued by a curious civil war, or rather a war between rival nobles and their adherents, the so-called “Hook and Cod Wars”. Amsterdam tried—successfully, as it turned out—not to get involved in this dispute by simply forbidding its citizens to talk about it. By an order of 26 December 1481, it was officially forbidden for anyone to say: “Thou art a hook” or “Thou art a cod”.
The war itself is curious enough (those interested in finding out more about it can do so here; you can either scroll down to 1349 or do a Find search on “cods”), but the fact that Amsterdam stayed out of it by forbidding people to talk about it is quite amazing. You won’t find a bigger believer in free speech than languagehat, but… it gives to think, as the ponderously facetious used to say.