“There is a lot of IED information generated by terrorists everywhere — websites, forums, people telling you where to buy fertilizer and how to plant IEDs,” said Hsinchun Chen, director of the University of Arizona’s Artificial Intelligence Lab. Chen’s “Dark Web” research project has found 500,000,000 terrorist pages and postings, including tens of thousands that discuss IEDs.

Chen and others aren’t sure how helpful blogs and message boards will be in uncovering planned attacks.