What you should definitely NOT say to Siri on Apple's iPhone and why

Social media pranksters have spent the past few days encouraging iPhone owners to say "108" to Apple's personal assistant, Siri. Those falling foul of the prank quickly found themselves scrambling for the end call button, however, as the voice command puts the user through to their country's emergency services.

While the dial code will appear fairly innocuous to most global iPhone users, 108 is India's version of 999 in the UK (or 911 in the US). As with many smartphones and their digital assistants, dialing any international emergency services number will re-direct the call to the equivalent service in the user's current region.

Those caught out by the simple, but incredibly ill-advised prank will have inadvertently placed calls to their local emergency services – but in some cases, the pranksters went one step further.

Although a lot of Twitter posts simply encouraged iPhone owners to "ask Siri about 108", others then suggested that you should also close your eyes for five seconds, leaving just enough time for the call to actually connect while Siri processes the request.

It goes without saying that you should not, under any circumstances, attempt this from your phone unless your need of emergency assistance is genuine. Fake calls are punishable under UK law, which defines a hoax caller as "a person who for the purposes of causing annoyance, inconvenience or needless anxiety to another, sends, or causes to be sent, by means of a public electronic communications network, a message that the person knows to be false."

Every call to 999 is recorded and can be traced, with the hoax caller – whether intentional or not – opening themselves up to prosecution, monetary fines and potential jail time. On a more fundamental level, however, frivolous calls made to emergency services could endanger others in vital need of immediate care or support.

In 2016, London's Metropolitan Police revealed that 66,000 prank and nuisance calls had been placed in the preceding 12-month period. The Met Police released audio extracts of some of the worst offenders to discourage non-emergency and hoax calls, which you can listen to here.