Folks! Be advised that anyone with VOIP is able to "spoof" their phone number. All of these companies that are sprouting up use this method.
Bill collectors, telemarketers and fraudsters are all using the same method. Those anonymous faxes, you guessed it! Same thing. If/when you call back to "request removal", you are in actuality confirming a "live number" to these people.
Bottom line; Don't answer the call. Common sense should tell you that if they really need you, they should know enough about you to have an alternate means of doing so. Regardless of the party might be.
Remember that you are not "legally" obligated to provide your phone number to anyone, under any circumstances. Not even people you are already in a "relationship" with.
Don't EVER call 800/877/866 (etc.) numbers, as they free for you to call but since the owner pays for the call they are entitled to having the information, and therefore entitled to disposing of it as they see fit. That could mean "selling it/leasing it" to someone else.
Change all your correspondence and vehicle registration, DL/ID to a PO Box. It's LEGAL in most jurisdictions, and highly illegal to obtain by circumventing the legal methods of doing so (Federal offense!). Make friends with the people at the USPS. They'll know, when someone show up trying to "hack" your POB.
Good luck everyone!