Another thing to think of is your trash is a good source of info on you. Not just for phone numbers, but for other paths to I.D. theft. We all need to get into the habit of shredding anything that has your name, address, and maybe phone number and especially Social Security # on it. As an example, every envelope, letter, bill header, and the like that we get gets that info torn off before going to the recycle bin. Those portions with info get shred. Don't forget about catalogs too, especially the order form inside that often has your info pre-printed. As an example of the phone number, it's often on your bill that gets tossed after payment. Also, as happened to me yesterday, my number was printed on the shipping label on the package I got from Speedway.
Some may think of this as paranoia, but it's a brave new world.