Handling Caller ID Spoofing? (Score 2, Informative)

There is a hardware product (google "Caller ID Manager") that costs about $100 which can enable white-list filtering on her phone. White list filtering means she enters a list of phone numbers she wants to ring through. Numbers not on her white list go either to voicemail or just get lost. This box wouldn't stop angry strangers from leaving a message, but it would stop them from ringing her phone.