A February photo shows Kim Jong Un meeting with army officials at an undisclosed location. (KNS/AFP/Getty Images)

North Korea's big "U.S. mainland strike plan," revealed in a photo from Kim Jong Un's war room, appears to mark the American cities that Pyongyang would attack when it launches its promised war against America. (Note: This plan is almost surely a bluff that would be way beyond North Korea's technical capabilities and, anyway, the "plan" is probably just for domestic propaganda.) It's not totally clear, but it looks as if one of the intended targets, among several West and East coast U.S. cities, could be the hip college town of Austin, Texas.

Austin might or might not actually be on the targets list, but all it took was this hint, this whiff of a possibility that Kim might plan on messing with Texas, to set off a fierce reaction among Texans.

The Twitter hashtag #whyaustin, asking why Kim had set his sights on the town, has been producing hundreds of reactions. The trend grew so quickly that even the official Twitter feed for the city government got in on the joke, tweeting "Not to worry Austin...we're prepared" with a link to a 1950s "duck and cover" nuclear safety video. Not all of #whyaustin jokes were funny, but a number were, and there's nothing like mocking a ruthless dictator to end the week on a high note. Here are some selections: