Edgar: Unless your phone number is unlisted, anyone can find out what it is. It's public information. But the way telemarketers work is by using an automated dialer. No one is in their call center dialing specific numbers by hand, nor do they look them up or purchase phone numbers from the phone companies. An automated dialer dials the numbers from telemarketer call centers. It dials multiple numbers at once, in large ranges. For instance, they will program the machine to call ALL numbers between 305-555-0000 and 305-555-9999. If your phone number happens to be in that range, your phone will ring. It has nothing to do with the phone company sharing your information.