Andrea this is not true, however they do register if your line is active.... Complain please to the DNC and help the RCMP and local police forces stop these people. Indeed they can use any number to display on peoples call display irrespective of what you do or don't do.
The DNC suggested that make up a list of all these numbers and the requisite information in a document or spreadsheet and send it to them every two weeks. I get these calls including the "Your computer is sending out viruse's" maybe once to twice a day and I just record the numbers.
Most of these guys are in India or some other place and could care less about any laws, some are right here in Canada or the USA like the Carribean skam/fraud.
Complain to the DNC list please as often as possible!!!!
Its a good idea to go on Google and search for your own name to see if you have gone someplace and given out personal information. Also consider Facebook and other media sites they are very insecure and others can see them no matter what anyone says to the contrary.
Many people find to there surprise that there name and other information including location is out there for anyone to see!
Also make sure your computer and Ipad device is free of viruse's, some can just stay there and record information and then send it back to these guys.
Consider if they call they already know your location, phone number and possibly much more information. How you might ask? Voting lists are public and list age, occupation of every person in a given residence as well there are other public sources of information so if someone says Hi Mrs. Jones and seems to know all about you this is why....
Google also allows them to see where you live (not real time) but its enough.... Get it??
Oh! Genealogy research that I love is also used by these people and investigators but for different reasons, they may not see real live people because of disclosure laws but then people put info in these sites including there locations, email address and sometimes even phone numbers.
So please complain to the DNC as often as you can it helps....