When publishing companies charge readers for access to articles in the scientific and technical journals they publish, the problem of access to what should be common knowledge and open to all is plain to see.
— David Harvey, in an seven-page article in the new Radical History Review, which you can access here from Duke University Press for $15.
Update: How the irony turns: Tony Harkney emails to point out that David Harvey makes the article available for free on his personal site.