Yes, I have. Literally hundreds of times. I lived in downtown Manhattan for a few years not too long ago (2010). Took the subway multiple times a day, every day. 1,2,3,4,5,6,A,C,R all the time. Metro-North to CT quite a bit one year as well. Never stopped or questioned. Saw some DHS uniforms maybe a dozen times over a period of 4 years? Maybe more, never paid attention as they just seemed to be minding their own business.

Have you ever been on the NYC subway? Has something changed recently?