An anonymous reader writes: An internal investigation by the TSA found that 95% of agents testing airport checkpoints were able to bring weapons through. In one case, an alarm sounded, but during the pat down, the screener failed to detect a fake plastic explosive taped to the undercover agent's back. ABC reports: "Homeland Security Secretary Jeh Johnson was apparently so frustrated by the findings he sought a detailed briefing on them last week at TSA headquarters in Arlington, Virginia, according to sources. U.S. officials insisted changes have already been made at airports to address vulnerabilities identified by the latest tests. 'Upon learning the initial findings of the Office of Inspector General's report, Secretary Johnson immediately directed TSA to implement a series of actions, several of which are now in place, to address the issues raised in the report,' the DHS said in a written statement to ABC News."