Did you know that it's easy and legal to send fake Caller ID information Neither did I.
It's illegal to use false Caller ID info to commit fraud. But stalkers can apparently transmit false ID info to get their target to pick up the phone, and pranksters and revenge-seekers can pretend to be whomever they like. Oh, lovely.
According to the article I linked to, the law that would make this illegal was passed by the House of Representatives, but is stuck in the Senate. IMO, they really need to pass this law. Tightening up the technology itself, to prevent anyone besides the phone companies from transmitting Caller ID information, is also a must, IMO.