High Court upholds retrospective legal fix for AN0M surveillance sting

The High Court of Australia has backed a retrospective law covering the validity of evidence collected using a compromised encrypted app named AN0M.

A large number of criminals used the AN0M communications app, believing that it was safe and secure.

The Federal Bureau of Investigation (FBI) had, in fact, taken control of AN0M during its software development, with the app containing a backdoor that forwarded copies of messages to law enforcement in Australia and the US.

At the sting's height, mobile phones running Google's Android operating system with the AN0M app installed were being used used to surveil more than 11,000 users worldwide, and 1650 in Australia alone.

The Australian Federal Police ultimately capturing around 28 million messages. It led to over 390 arrests and several prosecutions.

The permissibility of AN0M-collected evidence in criminal prosecutions was challenged late last year.

The government then passed legislation - known as a 'Confirmation Act' - that sought to reduce grounds for the challenge.

It was questioned [pdf] in the High Court "whether judicial power has been usurped" and "whether the Confirmation Act unduly interferes with, or "infringe[s]" the exercise of judicial power by courts."

However, the High Court declined to find the law was invalid, paving the way for AN0M-collected evidence to be used in prosecutions.