Call Hunting as advertised by the VoIP is dangerous because it is approached too glibly.
The industry is promoting the concept of consolidating voicemail into your VoIP voicemail in conjunction with call hunting. However, if any of the numbers which are rung in the search to find you have voicemail which picks up, that will cause your message to potentially get scattered anywhere and everywhere.
And if you are inclined to include a cell phone number in the list of hunted numbers, that is gambling big time. Think about it. When your cell phone provider's towers can't find your phone, calls go straight to voicemail without even ringing your phone. If you have one of those carriers (like Sprint) which uses technology which sends signals which can't get into buildings, then even if you think you have a phone which is on and waiting for calls, that may be erroneous in terms of receiving the calls in real time. If your batteries are weak, or if your cell phone goes into a power-saving mode and powers down, or if you are out of range or your signal is too weak when the call comes in, then the voicemail on your cell plan is where your calls are going to go. Your phone will not necessarily even ring, even if you are carrying it and waiting for the call. That will short-circuit the hunting sequence.
And then there is the current (Feb 2007) implementation of hunting such as Voicepulse has, which delivers a false busy signal if the hunting fails to find anyone to answer any of the lines being called. Somehow, Voicepulse considers this an acceptable design, not a flawed design. I personally consider delivery of false busy signals to be a form of deceptive advertising, a king of pretense that something productive is being done by the VoIP provider in locating a number at which a human is taking calls (or at which voicemail is taking messages).
So, one risk with call hunting is that your messages will end up on someone else's voicemail if you incluce any numbers of other people in the list. Another risk is that your cell phone will abort the hunting sequence even though the next number in the sequence which you have programmed might be a landline at which you could have actually taken the call in real time. And there is the Voicepulse version of "finding you" which will encourage your callers to keep calling by delivering false busy signals. (Voicepulse as I tested it in early February 2007 will not even begin the hunting process if you have its voicemail turned on, despite what their advertising says, and they seem determined to ignore my reports that it is not working as advertised.)
So, it seems to me that the industry needs to provide advisories and warnings about the risks of using the call hunt/find me feature.