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?

I take the train daily. I've only ever seen random cops walking around, setting up bag check tables in stations and infrequently armed swat guys on patrol. They never stop people and are more there as a show of force. The subway is no where near how awful the airports are.

Where are their bag check stations? I think I remember seeing this once or twice during Halloween and such by Times Square, but never in any other instance. Unless this is a new thing in that last year or so.

Usually in larger stations and it is really infrequent. It's usually a bunch of patrol cops with a plastic folding table and they set it up in the station outside the turnstiles. They'll "randomly" select people and check their bags. I've seen them in Queens (Roosevelt/74th) and other random stations.