Greek navy seals patrol the harbor of Pireaus. Though security was heavy it was not intrusive. Around Athens there were soldiers and police with machine guns but they seemed so relaxed that they did not seem threatening to visitors, even those from countries where armed men on the street are never seen. Most of the security was undercover. The result was that the subject of terrorism which was on everyone's minds before the Olympics was rarely thought about during the Olympics except by those whose job was to deter it.