Two incidents of “suspicious videotaping” of a European mass-transit system this year prompted a U.S. government warning to domestic homeland security officials this week about possible terrorist surveillance. The unclassified Department of Homeland Security “public-sector notice” did not describe the incidents or where they occurred, but said they took place in the past 120 days. The bulletin, issued Tuesday, said the episodes provided “indications of continued terrorist interest in mass-transit systems as targets and potentially useful insight into terrorist surveillance techniques.” Full Story