Rush hour on the New York subway and space is at a premium.
Yet despite the crush, some passengers - men, usually, it is alleged - want to take up more room than is entirely necessary by spreading themselves across more than one seat. They are seemingly oblivious to what they are doing, or else they don't care.
But now, a grassroots campaign against so-called "man-spreading" - the habit of male passengers parting their legs and placing them in a "V" - is about to get a boost. With their efforts previously confined mainly to blogs and social media, anti-man-spreading campaigners are to get official support, according to a report in the New York Times.
The Metropolitan Transportation Authority is set to launch a series of public advertisements that encourage men to "share a little less of themselves". One of the adverts implores male passengers: "Dude, stop the spread please. It's a space issue."
Among the anti-man-spreading "activists" featured in the article are Kelley Rae O'Donnell, an actress in her 30s, who takes photographs of offending male passengers and posts them on social media.