Just a note of awareness -
I recently found that my phone bill had increased by 25% because my PC had (unknown to me) been quietly dialling a premium-rate number while I was on-line.
While I can't take the kind of revenge I'd prefer, I have called my phone service provider (British Telecom) to block my phone from calling premium-rate numbers.
If you have an itemised phone bill, then check it to make sure you're not being ripped off by these dickless nerds.