Cartastrophe is a blog by Daniel Huffman that critiques bad maps:

There are a lot of bad maps out there. They lurk in brochures, on company websites, and in magazines. They confuse, they miscommunicate, and they make it hard to learn anything about the world. Sometimes they leave off Sicily. They’re made by people who have to rush against tight deadlines, by people who are pressured by their bosses to make bad design choices because it “looks cool,” and by people who were thrust into map-making jobs without any training.

I don’t hate these people. This site is not about attacking them. It’s about poking fun at their work, analyzing what went wrong. It’s never personal. A lot of work goes into making maps, even disastrous ones, and I have a good deal of respect for the people who go through it. I’m one of them, and I proudly feature one of my own works on this blog as an example of a few things not to do.

He does try to say at least one nice thing about each map.

Previously: GIS Web Maps to Critique Web Mapping Applications.