The Federal Government has used the mobile phone tracking ‘Triggerfish’ gadget for years now, and sometimes with great success. That’s because its an effective, invasive piece of hardware: by posing as a cell tower Triggerfish is able to quickly glean valuable identifying data from phones. Like phone taps, this had previously been thought to have been used only with the telcos’ approval, and after law enforcement officials had found “probable cause” to monitor someone. That supposed caveat was a minor comfort to privacy hounds, but as is so often the case with these things, might have been, shall we say, slightly optimistic.