Within a couple months of acquiring my cell phone, I started getting a lot of phone calls identified as “Restricted” - i.e. the caller was blocking the Caller ID. I have to assume that these were either telemarketers or bill collecters who had somehow gotten my number.
Granted, this was probably my own fault - I “fell for” one of those “Get your free laptop” banner ads on a Web site. I knew better, but I thought, just for fun, that I would work my way through their maze of forms and signups and questionaires and see how long it would take me to actually get to the part about acquiring this free laptop.
I did eventually give up, but by the time I did I had filled in my address and phone number a few times. Within a month my cell phone was ringing several times a day, and all the callers had “Restricted” numbers. There was an increase in spam e-mail too, but I have really good spam filters.
So I just headed over to the National Do Not Call Registry, and the calls stopped within a month.