The U.S. expelled two security guards at Iran's mission to the United Nations last week for activities "inconsistent with their official duties," a euphemism for spying. The State Department says the pair were caught videotaping New York City landmarks and sensitive infrastructure, including a key subway tunnel. And the event may not be an isolated one. Senior federal law-enforcement sources tell TIME it's just the latest in a spate of incidents of suspected "pre-operational surveillance" by people thought to have links to Middle Eastern extremist groups.
Individuals seen taking photos of landmarks and other potential targets are not usually arrested...