Frightening report from NPR's website:A scary anecdote from Iran. A trusted colleague - who is married to an Iranian-American and would thus prefer to stay anonymous - has told me of a very disturbing episode that happened to her friend, another Iranian-American, as she was flying to Iran last week. On passing through the immigration control at the airport in Tehran, she was asked by the officers if she has a Facebook account. When she said "no", the officers pulled up a laptop and searched for her name on Facebook. They found her account and noted down the names of her Facebook friends.
This is very disturbing. For once, it means that the Iranian authorities are paying very close attention to what's going on Facebook and Twitter (which, in my opinion, also explains why they decided not to take those web-sites down entirely - they are useful tools of intelligence gathering).
Social networking can empower political opposition and dissidents. But it can also help security forces track them. During the red scare witch hunts in the United States, suspected communists were asked to name the names of friends and relatives in the party. These days, the authorities could just check out your Facebook or MySpace pages.