Activists who chained themselves to lobby turnstiles at the Patrolmen’s Benevolent Association headquarters in lower Manhattan last week got a lot of mileage when 10 of them were arrested.

In today’s anti-police climate, when Black Lives Matter like-minded groups seem to sprout up like crocuses or weeds, depending on your view, the Black Youth Project 100 New York chapter rattled the PBA. And it seems the protesters preyed on the generosity of a potential ally, duping the New York Civil Liberties Union — housed in the same building as the PBA.

The activists said they were protesting the killing of Delrawn Small, shot by an off-duty cop after Small approached the cop’s car in a road-rage incident. But why did protesters rally at PBA headquarters and not at Police Plaza or City Hall, where police policy is set?

“We want the PBA to understand there needs to be accountability for racist, killer cops,” group co-chair Jewel Cadet told the media.

Responding to the protesters, PBA president Patrick Lynch said, “Today’s protest was a display of misdirected and misinformed anger that should have been pointed at City Hall, not the police officers who were on hand to protect the demonstrators’ First Amendment rights.”

One of the union’s grievances is that NYC’s anti-police climate stems from former Mayor Michael of Bloomberg’s overuse of stop-and-frisk.

At the Wednesday morning sit-in, it seems protesters misled the NYCLU. Apparently, protesters mistakenly believed its members needed security passes to enter the building. To obtain them, the group contacted the NYCLU the weekend before the demo.

So the NYCLU set up a meeting and placed the names of the people from the email on the building’s guest list. On Wednesday, the NYCLU staffer who was to conduct the meeting entered the building with the demonstration in progress. But she had no time to watch as she rushed to her office for what she thought was her meeting.

When no one showed up, the staffer realized the people she was supposed to meet with were participating in the protest.

One of those arrested called out to the staffer, asking whether she was the person they were supposed to meet with and then said, “Sorry about the meeting.”