Unscrupulous telemarketers (mostly based outside North America) are actually using the list as a source of names to call. In Canada, the CRTC (government body) requires telemarketers to pay a fee (dependent on which area/how many names) to download a DNC list with a risk of a $15,000 fine if they call anyone on the list. Some of these low-lifes are paying, for example, $50 for 600,000 live names on the Toronto list--it's a telemarketer's wet dream!
And just now, I stumbled upon a website whose only business is to supply telemarketers with DNC lists at wholesale prices! They are registered with the national DNC, download a fresh list each day and then resell the names at a discount to anyone who wants the names. Kind of restores you faith in humanity, doesn't it? Now, you know why you're still gettting calls.
And unless these people are based in the country they are calling, there's nothing anyone can do about it--they are out of the jurisdiction of authorities.