"Metacrap" is a very strong, coherent, pointed critique of the dream of metadata.

Cory Doctorow - People are lazy, so they misclassify because they can't be bothered to properly classify.  We can't all agree; everything is miscellaneous, as you say, so we can't all agree on the best way to classify information, and so on.  So, that's a kind of sampler of the reasons that the idea that we'll all make it all work is so flawed.

They are just a lot of categories of information that we can't draw lines between. . .