The title to this thread is misleading - it implies that this device is used routinely, which I can't see any evidence of.
There is definitely something embarrassing in that FOI material. Doubly embarrassing is that they need to use the bill to withhold it, which says they did something shady and didn't consider how to keep it out of FOI (which no self-respecting gov't official ever does - it's a hallmark of professional incompetence.)