MTA Police have been spying on peaceful Black Lives Matter protesters.

According to documents obtained by The Intercept through a Freedom of Information Law request, undercover cops monitored roughly two dozen demonstrations last winter. Police would take pictures of protesters in Grand Central Station and Penn Station, and create files on these protesters, who have otherwise broken no laws.

"I think it's just another example of how anyone who is practicing their constitutional rights and speaking against the government is going to be considered a domestic problem," Jose LaSalle, whose picture appears in one of the files, told The Intercept. "It's sad we have to be targets of surveillance when we're not committing crimes."

Sad but not surprising: New York police have a long history of spying on political movements.

NYPD Intelligence Division Detective Wojciech Braszczok posed as an Occupy Wall Street protester, attending birthday parties and happy hours with law abiding people who considered him a friend (Braszczok was recently sentenced to two years in prison for his role in the West Side Highway biker melee in 2013).

Earlier this year the Times reported that the NYPD was aggressively questioning citizens who attended Black Lives Matter protests, an apparent violation of the Handschu Decree.

The Handschu Decree was imposed by a federal judge in 1986, and prevents the NYPD from retaining information on political speech if it does not directly relate to criminal activity.

The documents obtained by The Intercept show that the MTA police are working closely with the NYPD and its Intel Division, but the extent of the collaboration is unknown, in part because of redactions.

In addition to the activities of a Lower Manhattan high school that participated in the protests, transit police also kept tabs on Alex Seel, a protester who is described in the article as a "quiet photographer."

“He doesn’t do any of the planning. It’s very telling," Seel's friend told The Intercept. "If they’re focusing on someone who’s a silent supporter, I can’t imagine what they’re doing to people more at the forefront.”

An MTA spokesman emailed us this comment:

The Metropolitan Transportation Authority Police Department must ensure the safety and security of millions of people who pass through our railroad systems every day, at a time when transportation networks have been persistently targeted by terrorists. We accommodate peaceful protest in our transportation system, while also ensuring that protest activities do not prevent customers from using the system for transportation. We take all appropriate police measures to ensure the safety and security of our customers, but we do not discuss the particulars of those operations.