Four in the evening

1. The Washington Post reaffirms its allegiance to impartial journalism with a new social media policy. WaPo

2. Tehran Bureau has teamed up with Frontline to expand coverage of Iran. NYT

3. Read a banned book, it'll be good for your soul. Scott Martelle

4. Given the challenges we face in Afghanistan, it's time to take a closer look at Yemen. Time

Police clash with Iranian protesters

Iranian authorities are trying to clamp down on the now daily protests in Tehran. Here's a few options to keep up to date on what's going on:

Borzou Daragahi and Romin Mostaghim are still in Tehran for the Los Angeles Times.

Andrew Sullivan at the Daily Dish is scouring Tweets from Iran.

The New York Times is filing reports from inside Iran.

Robert Mackey at the NYT's Lede blog is also following updates from social networking sites.

Updates from Tehran Bureau, an independent site with original reporting, commentary and citizens.

Washington Post has a reporter in Tehran.

Nico Pitney from Huffington Post is live blogging the protests.