Amazon's Ring has provided doorbell footage to police without owners' consent 11 times so far this year

Amazon's smart-doorbell company, Ring, has provided surveillance footage to law enforcement without a warrant or the consent of doorbell-owners 11 times this year alone, according to a letter Amazon (AMZN) sent to Congress earlier this month.

The disclosure highlights the degree of Amazon's control over data generated by the doorbells' cameras and microphones, as well as its deepening relationships with thousands of police departments across the country.

The July 1 letter responding to questions by Sen. Ed Markey and made public by his office on Wednesday shows that Ring frequently makes its own "good-faith determinations" as to whether to provide surveillance data to law enforcement absent a warrant or the consent of the doorbell owner.