Thank you to everyone who joined us at Birmingham Open Media (BOM) on Wednesday for our exploration of how the police are covert surveillance technology known as IMSI catchers to spy on hundreds of mobile phone users at a time. Here’s a round-up of the evening, in case you missed it or would like to know more.
Surprise at police surveillance capabilities
It’s probably fair to say people were shocked at just how powerful IMSI catchers are. Even in their most basic form, they allow anyone with access to one to ‘hoover up’ the unique IDs of hundreds of mobile phone users in a given area. There is evidence the police are using IMSI catchers at peaceful protests, a clear infringement of our civil liberties. More advanced models support the interception of voice calls, text messages and email and even allow authorities to deploy malware (essentially a computer virus) onto people’s phones.
Secrecy and dubious legality over IMSI catchers
Attendees were also struck by the secrecy which surrounds the use of IMSI catchers. The West Midlands Police, in line the Metropolitan Police Service, will not confirm or deny their use, citing national security and the risk of alerting criminals to the methods they use.
The secrecy surrounding the use of IMSI catchers has made it hard to determine whether it is legal for the police and other authorities to use them. In 2015 the Home Office asserted their use is covered by several laws, notably the Regulation of Investigatory Powers Act 2000 (known as RIPA). The recently passed Investigatory Powers Act 2016 (AKA the Snoopers’ Charter) was intended to replace RIPA but it’s still unclear whether IMSI catchers are covered by the new law.
Even if IMSI catchers are covered in the laws above, there’s a very good chance their use could be viewed as disproportionately interfering with people’s right to privacy and freedom of expression. Last December, The EU Court of Justice ruled that the UK government had broken the law by indiscriminately collecting the nation’s internet activity and phone records. It’s likely that police use of IMSI catchers
Putting aside the issue of legality for one moment, the sheer secrecy surrounding the use of IMSI catchers makes it very difficult to know whether the technology is being used appropriately. We don’t know, for example, whether the West Midlands Police limit the use of IMSI catchers to the most serious criminal cases against a clear target or if they are used on an ongoing basis to monitor particular communities or groups in Birmingham.
What little we know about police use of IMSI catchers is the result of investigative journalism (especially some great work in 2016 by The Bristol Cable), campaigners searching for IMSI catchers and MPs asking questions in parliament.
Please find below a link to the slides from our presentation. The slides are currently only in pdf format. We’re still working on a more mobile-friendly way to share our stuff without going to the dark side (Google/LinkedIn, etc) 😜. Please get in touch if you have any good suggestions.
Tips for protecting your privacy
Unfortunately there’s not a lot anyone can do to prevent their mobile phone being accessed by an IMSI catcher, other than switching off your phone and removing the battery.
Luckily, there are some simple steps you can can take to improve your overall online privacy and security. For example, switching from SMS texts to using Signal private messenger will mean all your messages are encrypted. That way, if the police (or anyone else with an IMSI catcher) were to intercept your messages, they wouldn’t be able to read them.
Our 7 top tips for protecting your online privacy and security is a good place to start.
For more in-depth information and advice on defending yourself against surveillance, check out EFF’s Surveillance Self-Defense guide. On the site you’ll find tailored guides for journalists, activists and other groups at particular risk of surveillance as well as general advice aimed at everyone.
Watch the Phone Hackers documentary in full
We showed part of the VICE News documentary, Phone Hackers: Britain’s Secret Surveillance. You can watch it in full below.
Links to further reading
We covered a lot of ground in our presentation and discussion about how the police are using IMSI catchers to access people’s mobiles phones. For those of you who’d like to explore the topic in greater depth, here are some links to further reading: