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As protesters swarmed D.C. Monday afternoon, Jennifer Gelber, a design-firm employee on her lunch break near Union Station, noticed police on 2nd Street NE milling around a blue fabric bag. It was a suspicious package, they told her. So when Gelber and her co-workers spotted another on 3rd Street NE, they alerted the nearest officer. The parcels were attached to smaller, hard-sided cases that had digital readouts. “For a very brief moment there was this hysteria about all these bombs,” Gelber says. Police spokesperson Sgt. Joe Gentile says he heard nothing about the event. As it turns out, the devices were not meant to cause disruption but to detect it: They were Instatel-brand BlastMate seismographs, which are used by “blasters, vibration consultants, [and] quarry and mining experts,” according to the company. On Tuesday afternoon, some of the bags were flanked by purple and orange flags reading, “Please don’t touch.” —Joe Dempsey