Instead of looking for uniforms around critical sites, watch for those younger men and women -- many with military haircuts -- and a kind of sleepy, "I'm just hanging around" look about them. They'll have concealed side-arms and maybe an earbud, like most young people. Watch to see if occasionally they will walk and chat with an older man or woman; those are the senior NCOs and Warrant Officers. Go ahead and try your powers of observation and see what you may see. Above all, don't go up to them and break their cover.