he U.S. Border Patrol said that smugglers are using drones to spy on its agents along the U.S.-Mexico Border between San Diego and Tijuana.

“They’re gathering intelligence, they’re doing counter-surveillance on our agents, they’re trying to see our work patterns, how many agents and what they’re doing,” said Border Patrol Agent Diana Ibarra in a recent bulletin published by the federal agency. “They’re working to try and find any possible vulnerability and exploit those.”

She added that the use of drones for such purposes is not an isolated incident.