In order to visit the Statue of Liberty, one must first go through a security check that includes going through a special "smell" detector having first removed all metal items including belt, coins and even shoes. The detector presumably checks our whether or not one is carrying explosives.
Penn Station, one of the main train terminals in NYC has armed soldiers at each entrance as well as the usual Police.
JFK requires the removal of belts, shoes and watches when going through security.
As an Israeli, I found it fascinating to note the approach that the Americans are taking to security, particularly around New York. Despite being used to opening my bag and having a metal detector run over me every time I enter a public building, I was still surprised to be asked to take off belt and shoes at certain locations - at the Israeli equivalents - Ben Gurion Airport and The Knesset for example, I had never witnessed security that exacting.
The security services are of course intended to stop acts of terror but no less important is that they should give the people who they are protecting a feeling of safety. I couldn't help wondering whether people felt safer as a result of the strict measures or that the threat was far greater than it really was. Several years ago I flew into England to find troops in the terminal and light tanks outside as a result of an IRA warning. Friends joked that I should be used to it being Israeli but I certainly don't remember seeing armoured vehicles parked at Ben Gurion and felt, as I do to an extent about the American examples that I've mentioned, that an element of paranoia might have crept in, but perhaps thats just my perception as someone who is used to living under a certain threat.
Every country is perfectly entitled to defend its citizens as it sees fit. I'm sure the Americans have taken the best possible (by which I mean Israeli) advice. Just interesting to note the difference.