The federal government has been secretly tracking immigration activists, immigration activists, lawyers and journalists covering the topic, KNSD-TV, an NBC station in San Diego, reported on Wednesday evening.

Leaked documents from a Homeland Security source showed that the U.S. created and maintained a secret database of activists, journalists, and social media influencers the government had associated with the migrant caravan that traveled from Central America to the U.S.-Mexico border at the end of 2018. Following the event, a number of people who were among the 50 in the database said they seemed to be targeted for higher scrutiny at the border. Most of the people monitored are U.S. citizens.

Early in 2019, two journalists and two immigration rights attorneys who had worked with members of the caravan were denied entry into Mexico, according to the Los Angeles Times. Their passports had been flagged.

The leaked documents show that agents from Customs and Border Protection, Immigration and Customs Enforcement, the U.S. Border Patrol, Homeland Security Investigations, and the Federal Bureau of Investigations all used the database. The use was under a code name of “Operation Secure Line,” which designated the efforts to monitor the caravan.

Also involved was the International Liaison Unit, which coordinates work between U.S. and Mexico intelligence organizations.

Each record had a picture of the person and various information. Some of the images were marked with a red X, indicating that they had been interviewed, arrested, or had a visa revoked.