Caller ID spoofing

Every now and then a new technology comes around that makes everyday life easier. Inevitably, someone else comes along and ruins it later. A company called star38 will soon introduce a service that allows callers to spoof caller ID information sent on a per-call basis. According to the company, sales will be limited to private investigators and collection agencies.

While star38 might limit their service to "legitimate" users, I don't see what is stopping other companies from using the technology one way or another. What is to stop telemarketers from using a similar service to make marketing calls appear to come from a family member?

This changes the trustworthiness of caller ID to, say, that of email. Which we all know can never be spoofed.