Last year, BT handled 31 million calls, while a further six million were handled by Cable & Wireless. Half of those, though, weren't put through to the emergency services because 999 had been unintentionally dialled from people's mobile phones or they were prank calls.
Unfortunately, I have on two occasions mis-dialled the emergency number from my mobile. I don't think it's my fault though - it's the result of an emergency number chosen long before mobiles were invented.
Firstly, in many [?all] phone models, even if your mobile is locked if '999' is input the phone automatically unlocks and is able to call the number. Secondly, if pressure buttons are accidentally pressed whilst, for example, the phone is in your pocket, pressure is most likely to be repeatedly applied to the same area. A combination such as '999' is far likelier to be accidentally dialed than '157' or '348', for example.
It seems this is a serious problem since there are 15 million or more accidental calls each year. This must cost a large amount and potentially delays responses to genuine calls. Two things - stopping phones from automatically unlocking, and changing the emergency number to something like '911', would likely cut down accidental calls significantly. Good idea?