I disagree that only 4 digits should suffice, after all, that means that once there are 10,000 simultaneous conferences going you can basically just try pins at random and see whose huddle you drop in to. And with less conferences the chances would still be pretty good, just try a couple of times.
The pin is the only thing between an outsider and your conference. (assuming the phone number is the same, which seems to be the case right now).
The pin is the only thing between an outsider and your conference. (assuming the phone number is the same, which seems to be the case right now).