IMSI catchers: PI's legal analysis

We analyse how the intrusive and unregulated use of IMSI catchers infringes on our right to privacy, freedom of expression, and freedom of assembly and association.

Key findings
  • IMSI catchers are intrusive surveillance tools whose use remains unregulated.  
  • They are often deployed in secret, without a clear legal basis, and without the safeguards and oversight mechanisms.
  • Their use infringes on our right to privacy, freedom of expression, and freedom of assembly and association.
Report
cover of legal analysis pdf

The majority of people today carry a mobile phone with them wherever they go, which they use to stay connected to the world. Yet an intrusive tool, known as an International Mobile Subscriber Identity catcher, or “IMSI catcher” is a form of surveillance equipment that enables governments and state authorities to conduct indiscriminate surveillance of mobile devices, and by extension, on users.

IMSI catchers can do much more than monitor and intercept mobile communications. Designed to imitate mobile phone towers, they also entice mobile phones to reveal their IMSI and International Mobile Equipment Identity (“IMEI”) data, which is data tied to individuals. This allows otherwise anonymous people to be readily identified, and their locations to be tracked.

The government use of IMSI catchers has major implications for our fundamental rights, not least because as with other indiscriminate forms of mass surveillance, IMSI catchers have a chilling effect on civic society.

In this legal analysis, we examine how the intrusive and unregulated use of IMSI catchers infringes on our right to privacy, freedom of expression, and freedom of assembly and association, as guaranteed under international human rights law.

IMSI catchers are often deployed in secret, without a clear legal basis, and without the safeguards and oversight mechanisms applicable to surveillance activities under international human rights law.

To date, there has been insufficient public debate about the scope and nature of government IMSI catcher use, including the extent that this surveillance technique interferes with human rights in a democratic society.