Just as e-mail spoofing can make it appear that a message came from any e-mail address the sender chooses, caller ID spoofing can make a call appear to have come from any phone number the caller wishes. Because people are prone to assume a call is coming from the number (and hence, the associated person, or persons), this can call the service's value into question.
This on-line service has prompted law makers to propose a bill to make this practise a crime:
(1) Phone spoofing
This bill has already cleared the full House and the Senate Judiciary Committee would criminalize faking Caller ID if:
(A) the phone number belongs to an actual person who did not provide prior consent.
(B) you intend to commit fraud.
If enacted, the "Preventing Harassment Through Outbound Number Enforcement" bill, or PHONE Act, would carry penalties of up to five years in prison and fines of $250,000.