If you are cold calling to sell services, you shouldn't be reluctant to provide valid caller information. The only conclusion we can draw from people who don't is that you are dishonest scumbags.
Noisy construction jerks. Never ever hire any construction types who call over the phone. They are casing your neighborhood and if you engage any of the companies, crime will go up in your area. They will call to see if you are home, if you do not answer, they send someone to case your property. Have evidence of this on video camera that I turned over to police.