Disconnecting your phone line from the ooma hub

Ooma's promotional material states that White Rabbits and purchasers during the promotional period must have a landline which they allow to be used by Ooma for other subscribers' calls.

However, it is not clear what technically prevents a user from saying that they have a landline but simply disconnecting it. If the Hub contains some sort of mechanism to detect the absence of a landline, it would likely be a simple matter of defeating it. This could be done simply by connecting the depicted circuit across the phone jack on the Hub (thus allowing the subscriber's phone line to directly connected to the phone for their private use). Depending on the setting of the switch, this would appear to the Hub as a phone line which doesn't return dial tone, a line that is always busy, or a disconnected line.