Service provider collaboration: Mobile network operators

You can use anonymous phones to make it harder for mobile network operators to provide useful information to an adversary.

You can follow digital best practices to make it harder for mobile network operators to provide useful information to an adversary. For example, you can:

• Not use a phone, or leave your phone at home.
• Use end-to-end encrypted messaging applications on your phone, instead of traditional SMS and calls.

You can encrypt “in-motion” data to make it harder for mobile network operators to provide useful information to an adversary.

Investigators used the collaboration of mobile network operators to geolocate approximately 30 phones and intercept their calls in real time.^[3] In particular, investigators used the intercepted calls to:

• Hear about a meeting outside apartment buildings, set up physical surveillance of those buildings, and arrest two people who went to the meeting.
• Hear Louna make an appointment with a doctor, then contact the doctor to obtain Louna's personal information, including her address and phone number.

Investigators used the collaboration of mobile network operators to intercept calls from Boris's phone or the phones of people close to him.^[4] They regularly listened to the intercepted calls in real time and used information from the calls to adjust ongoing physical surveillance operations.

Investigators used the collaboration of mobile network operators to geolocate the phones of the defendants and of people close to them in real time and to record unencrypted phone conversations.^[5] In particular:

• In one case, investigators could not determine the phone number used by one of the defendants, but had determined that the defendant often moved around with another person, so they geolocated the other person's phone in real time to locate the defendant.
• In one case, investigators followed one of the defendants as part of a physical surveillance operation, but lost sight of them. In the following hour, they geolocated the defendant's phone in real time to locate them. As a result, one hour after losing sight of the defendant, investigators regained sight of them and resumed the physical surveillance operation.

Investigators used the collaboration of mobile network operators to:^[3]

• Establish links between people.
• Geolocate phones in real time.
• Record a large number of phone conversations, including conversations that took place between the moment a call was placed and the moment it was answered (i.e., while the phone was ringing).
• Identify the phone numbers that were active around Bure during three demonstrations that took place there in February, June, and August 2017, including 55 numbers that were active during all three demonstrations.

Investigators used the collaboration of mobile network operators to link phone numbers to civil identities, to know which phone numbers were in contact with each other, to geolocate phones (both retrospectively and in real time) and to record phone calls.^[6]