The WSJ reports that the Iranian regime is monitoring and threatening its global diaspora through online portals such as Twitter and YouTube. Here is one story of many:

His first impulse was to dismiss the ominous email as a prank, says a young Iranian-American named Koosha. It warned the 29-year-old engineering student that his relatives in Tehran would be harmed if he didn't stop criticizing Iran on Facebook. Two days later, his mom called. Security agents had arrested his father in his home in Tehran and threatened him by saying his son could no longer safely return to Iran. "When they arrested my father, I realized the email was no joke," said Koosha, who asked that his full name not be used.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.