First up was 40 Broad Street. A 25-story office building completed in 1982, it once had three geometric planter-and-bench installations at the back of the property, offering a quaint-for-downtown public oasis.

Some two decades later, the seating was removed to allow for a condominium conversion, which ran into financial trouble. All that remains are their outlines, visible in the concrete that fills the gaps where the planters were jackhammered out.

Not only was there nowhere to sit, but people, including members of the building staff, also began using the now-barren plaza as a parking lot, all but eliminating any possibility of public use. Asher Zamir, the developer, said he did not know anything about the planters and referred questions to his management company, FirstService Residential, whose representatives did not respond to inquiries last week.

Sometimes a public space can get lost inside the city’s bureaucracy.

A spokesman for Morgan Stanley said it had shuttered its space for security reasons, and noted that the closing was approved by the city’s Department of Buildings. But it is another agency, the Department of City Planning, that regulates privately owned public spaces. That agency said that it was unaware of the closing until I contacted it, but that it was now investigating the matter.

“We expect public space to be managed as such,” Wiley Norvell, a spokesman for Mayor Bill de Blasio, said in an email. “The city has taken operators to court in the past to get compliance, and if necessary, will do so again.”

Indeed, after the column about Trump Tower, the city issued yet another violation for the atrium encroachment carrying a $2,500 fine. An administrative hearing was scheduled for Sept. 3, but no one from the Trump Organization showed up. The hearing had to be rescheduled, apparently because the city sent the hearing notice to the wrong place.

The same day, Mr. Trump held a campaign rally for himself in the Trump atrium — where velvet ropes and guards further blocked off the space to both pedestrians and protesters.