This is rather amusing. Cologne isn't that big a city but I don't recall there being a red light district when I visited the city in 2003. I guess it wasn't mentioned in my guidebook. Heh.

Media banned from red light district

The German city of Cologne has banned foreign press from its red light district in the run-up to the football World Cup, after prostitutes complained about journalists chasing away their customers since British media reports raised global interest in local "drive-in brothels".