Obama arrives with Secret Service agents in tow

Governments are often eager to watch out for online threats, but it's sometimes tough to spot the real dangers when the internet is rife with sarcasm; just witness the confusion when someone jokingly threatens to blow up an airport. For the US Secret Service, spotting humor is important enough that it has posted a request for automated Twitter monitoring software that, among other things, detects "sarcasm and false positives." In theory, officials wouldn't have to read every poor attempt at comedy just to find the few tweets from those who mean real harm.

The proposed technology wouldn't just be for identifying sarcastic posts. A spokesman tells the Washington Post that the tool will help the Secret Service gauge its online influence, and even address complaints. If such code had been available during the President's 2009 inauguration, for instance, the agency could have resolved a security bottleneck preventing people from getting in. We're a long way from seeing a finished tracking system in action, so it's tough to know how well it'll work -- it's difficult for computers to interpret literal meanings, let alone subtexts. If agents don't knock on your door after you make an off-color remark, though, you'll know the software is doing its job.

[Image credit: Saul Loeb/AFP/Getty Images]