Paris remains edgy after terror attacks earlier this year, and the appearance of five unexplained drones overnight isn't helping. "It could be a coordinated action, but we don't know yet," a police source tells the Telegraph of the devices, which were seen at well-known sites including the Eiffel Tower, US embassy, the Interior Ministry building, and the Louvre museum, the AP reports. The drones are commercial models which wouldn't cause harm by themselves, but that calculus changes quickly if extremists figure out how to attach bombs or chemicals to them. Dozens of sightings have been reported in recent months over French nuclear plants and military sites in the past few months, the AP notes; Paris has a ban on the flights. (A drone that crashed last month at the White House was not very nefarious.)