The police force covering Moscow’s subway system has proposed to deploy an IMSI (International Mobile Subscriber Identity) tracking system capable of monitoring the location and movement of mobile phones.

The police department has already begun deploying sensors that read information about the mobile phones of passengers as part of the system, according to Russian broadsheet Izvestia. Typical IMSI tracking systems are able to ping phones within several metres and collect the SIM identifier, which can then be linked to an individual.

Operations chief of the police department for the Moscow metro Andrey Mokhov told the newspaper that the objective of the system is to search for stolen mobile phones, but the report cited expert claims that its scope is much wider, and that the government will be able to monitor all passengers without exception.

Mokhov’s comments raise two questions: if criminals acquired a handset they would likely swap out the SIM, making such a system redundant. Secondly, mobile phone operators have the information and are able to perform similar tracking already. The police would just need a warrant.

The executive director of the Security Industry Association, Alexander Ivanchenko suggested that the system is not created for the search of mobile phones, claiming that the cost of the system is not commensurate with the value of all the stolen phones.

Legally, the police are not allowed to follow a person without appropriate sanctions, but they are able to keep track of property, such as a SIM-card, the report added.