Flock, the US surveillance firm, is rolling out new safeguards against police misuse of its technology, which founder and chief executive Garrett Langley admits should have happened sooner. Police have used Flock to track romantic partners and stalk strangers, prompting growing public backlash. Asked whether the company had taken too long to protect its tens of thousands of cameras, licence plate readers and drones from police abuse, Langley said "Yeah."