I have followed the above advice and do not discourage others from doing the same, though after several months, I have noticed no change. The worst offender calls almost on a daily basis, stating, "The FBI has noted a big increase in break-ins in your neighborhood. Let us put a sign in your yard and we'll install a security system, blah, blah, blah." They say it's at no cost, but they fail to mention the monthly monitoring expense. The FBI would not be interested in home break-ins, and there has not been an increase in my neighborhood. The robo-call gives you a chance to opt out by pressing a number at the given time. DON'T do this. It only secures the information that they have reached a working number and increases the calls.