Caller ID is our friend! We block all "unavailable" calls, and answer no calls from names we don't recognize. Once we get a message, as in back brace, new ID cards, or what ever the current scheme is, we block that number as well. Currently we are being bombarded by calls from numbers that are very close to our own. Same area code, and same 3 number prefix, usually using a local company name. Don't answer those either. If it's legit, they will leave a message!