Of course. But is *sounds* like Vonage is in fact telling people. There's no reason why the county 911 can't use CID on a non-911 line to access their database, except that they don't want to be bothered.
The point is that CID can be blocked and is not guaranteed to be delivered. The ANI information the 911 centers use is pretty much the same data that feeds the telephone company billing system. That information cannot be blocked or opted out of providing. Of course, if you want the PSAP to use CID information to take emergency calls on a non-emergency number and do the look-up from the CID it would be permissible to have the PSAP lines configured for Anonymous Call Rejection which would reject all calls that didn't have CID. That would insure the PSAP had at least some information to work with.
[TELECOM Digest Editor's Note: On 'regular' 911, attempts to use *67 in front of it are ignored. A good way to phrase it is that on calls to 911 the police always pay the bill (for the transit of the traffic) and they _insist_ on getting the numbers of the calling parties, just like on an 800 number; when someone else is paying, you get no choice in the matter. I notice an interesting thing about Vonage and *67 also. *67 _does work_, but if you do *67-something else you'll hear a distinct 'click' after the *67 has been dialed and a new dial tone from some different switch it sounds like to me, jumps in and takes the remainder of your dialing string. I dunno why ... but Vonage does not accept *67-911 either, so there is no way the caller ID in those cases would not get a story for its owners. PAT]