The New York City Police Department still has photos of Black Lives Matter activists years after the group was staging regular protests in the city, according to a public records request cited in a Thursday report from The Appeal. Advocates claim that the retention of these photos could violate the department’s own surveillance guidelines, known as the Handschu Guidelines, which prohibit the police from retaining photos taken at rallies unless they “relat[e] to potential unlawful or terrorist activity.” Given that the group became less active years ago, advocates say, there’s no reason the department should be legally allowed to retain those photos, many of which just include protesters milling about on the street.

Some experts are also concerned that the photos could violate activists’ First Amendment rights. “There are First Amendment questions about how long you can keep and access these photos,” Rachel Levinson-Waldman, senior counsel at the Brennan Center for Justice’s Liberty and National Security Program, told The Appeal. “How is it being used and kept? These practices could potentially chill First Amendment activities. I would have a concern if [photos of] basically innocent third parties are living in these files and being used for other reasons. What protections do they have?”