Jeff Jarvis has a good set of links on reaction to the arrest of Iranian blogger Sina Motallebi. What's particularly scary about the arrest is that Motallebi wasn't especially political. Here's a description of the blog's contents:
[H]is last few posts before being summoned were (in order) about Iranian newscaster's inability to pronounce names properly, retirement of the "out of this world champion" Michael Jordan, his son's teething problems and a reprint of an already published statement by Kambiz Kaheh, a film critic arrested on bogus charges of distributing illegal videos. Hardly risky material.
The most comprehensive way to follow the story, at least in English, is at Hoder.