From the MTA website home page, this image sums up the current situation, promoting simultaneously the campaign to watch for suspicious packages and beach trips on the LIRR:

Ahh, Summer in New York: beaches and amusement parks, automatic weapons and concrete barricades. Shall we go to the park or down in the bomb shelter? Stock up on beer or Cipro?
I did find that same odd juxtaposition on Sunday when we went down to Wall Street for the bike race, at the same time they announced the terror alert. I ran into three athletic guys that looked straight off the golf course: tan pants, blue polo shirts. The Glocks on their belts were a little odd, admittedly, until I saw the discreet "NYPD Anti-Terrorism" symbol on the shirts. Very different garb from the usual flak jackets and helmets, but they must want to send different messages in different situations: Kids, sleep soundly—our golf courses are safe tonight.