Credentialed press photographers in New York City have access to more places than the general public. An official Press Pass, obtained from the Police Department, can get them past police barriers in many cases (as long as they don't interfere and aren't in any danger themselves, obviously), press areas at public events, or other areas where photography might be restricted or a tripod permit required. I think the application just requires a letter from the editor of the publication or agency the photographer is working for. I'm not sure how this works out for, say freelance photographers not affiliated with an agency or bloggers.