The Grass Mud Horse is a Chinese dissident construct representing those who resist authoritarian censorship, particularly censorship of the Internet. The horses are visiting Iran. You can help them.
Twitter is a major communication resource for Iranian protesters. Twitter has delayed a major software patch to their service so as not to interrupt this communication. Because Twitter is an aid to the protests and in getting information out of Iran, the Iranian intelligence services are attempting to use it to entrap dissidents. You can do a little thing that might help. From Wired:
Help cover the [Iranian] bloggers: change your twitter settings so that your location is TEHRAN and your time zone is GMT +3.30. Security forces are hunting for bloggers using location and timezone searches. If we all become ‘Iranians’ it becomes much harder to find them.
Also, change your location if you filled it in. Pass this on – via email, not Twitter – to other twits you know.
An amusing bit here about the cyber battle in Iran. The Iranian Revolutionary Photoshop Guards still can’t get it right.