Programmable Dial-Out BlockingDevice
Premium rate numbers (in the UK, generally those starting with 09) are often used as a way of extracting payments from telephone users and Internet surfers. This is however illegal if it is done covertly without the knowledge of the user. The circuit described here blocks such numbers and cannot be defeated.Despite the best endeavours of consumer protection organisations there is still much abuse of premium rate telephone numbers. In particular, it can happen that while surfing the Internet, unbeknown to the user, a new dialler program is downloaded which terminates the call in progress and dials out again on an expensive premium rate number. Unfortunately dialler guard programs are no defence against such underhand activity, since as soon as some new piece of protection software appears it only takes the hackers a short while to develop a way to get around its security.