Ho hum. The facts then for CABLE BROADBAND
If you DON'T have an ORDINARY MODEM installed and you have CABLE BROADBAND then YOU CAN PICK UP DIALLERS BUT THEY WILL HAVE NO EFFECT (NO PHONE LINE TO DIAL OUT ON).
If you have CABLE BROADBAND AND AN ORDINARY MODEM installed then you are at risk when the ORDINARY MODEM is plugged into the phone line because the dialler can dial out on an unused modem that you have left conveniently plugged in to the phone line.
Diallers can and will install on any PC on any type of connection. Whats important is whether they have a conventional (DUN) modem to phone out on. The diallers phone telephone numbers (ordinary phone numbers like in the back pages of the papers) which carry high charges.
If you have a conventional modem installed then whilst you are not using it the diallers can ring out.
If you don't have one installed or it is unplugged from the wall diallers can't ring out.
ADSL BroadBand- Not sure.