Premium phone line regulator Icstis says phone companies are not doing enough to warn customers about internet "rogue-dialling" scams.
What exactly are the scams and how can people avoid falling prey to them?
How does the scam work?
Rogue dial-up programs are malicious bits of code that sit on a computer until it is connected to its usual internet service provider.
The program will then silently disconnect the computer and phone a premium rate number instead.
People still get internet connectivity but it can cost up to £1.50 per minute and victims of the scam often do not realise what is going on until their next phone bill arrives.
How do rogue dial-up programs get onto people's computers?
Providers persuade people to download the diallers by hiding them in other programs, or sometimes they exploit security flaws in web browsers and operating systems to install the diallers secretly.
In some cases the diallers are installed by programs hidden in spam e-mail or web pop-ups.
But sometimes the problem lies with people who have not read or understood the terms and conditions of software they install to download software, music or pornography.
How can you tell if this is happening on your computer?
By looking at the phone number the computer is dialling to connect to the internet.
The simplest way to tell is by checking every time a computer is about to connect to a telephone network that the number it is going to dial is the correct one.
Anyone with any doubts about such phone numbers can also check them on the Icstis website.
If you are on a broadband connection, you could make sure your dial-up modem is disconnected.
A more sophisticated check is to look at what applications are running because sometimes the dial-up software systems are running in the background and dialling without users knowing it.
You can see a list of the programs running on a Microsoft Windows computer by pressing the Control-Alt-Delete buttons at the same time and bringing up the Task Manager.
Programs to deter and remove rogue diallers, such as Spybot and Ad-Aware, can be downloaded from the internet for free.
What redress can I seek if I get caught out?
Phone companies say that, under the current system, once a call has been made there is little that can be done.
Icstis cannot demand pay-outs on behalf of phone customers, it can only close illegal services down.
Any companies found running a dialler without Icstis permission can be cut off immediately.
A government review of premium line services is likely to say Icstis should have more power to deal with rogue diallers in the future.
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