Yesterday, I got a call at 7:41 PM Eastern time: the caller ID showed "1-000-000-0000". I answered out of curiosity, assuming that it would be some political tripe.
The call was a recorded announcement from my local electric company, saying that I should report electrical outages to a certain number and blathering about how they're "doing our best" to prepare for a hurricane.
If this was a "Reverse 911" call, I think the Caller ID would be better used if it had been set to the number that I was expected to call in case of a power outage. If it was just another robocall, then it's a great example of how CID can be erroneous.