toothpaste. i have presented this in such a way that somebody giving it a casual inspection will probably pass it. >> the question of course is how good are the inspectors. how tight is security at u.s. amounts especially on russian soil. ivan watson is in sochi for us tonight. barbara starr at the pentagon. barbara the tsa issuing this ban today. obviously the u.s. taking this latest threat seriously. >> reporter: absolutely, anderson. good evening, the department of homeland security issuing this ban as they would say out of an abundance of caution. but the reality is now the u.s. and the russians are tracking several threats against the sochi games. and the challenge for intelligence services in both countries is to determine which of these threats are specific, which are credible, who would have the capability to really assemble some of these devices and carry off an attack. and they are far from understanding that at this point. so still a lot of intelligence gathering going on, a lot of focus on this toothpaste threat.