Insulation piercing connectors

[AndyD]

I've recently seen it in an domestic home installation where it kind of taps of the live wire going into the prepaid meter and the other going to the distribution box.

Also strange that you can save money with it. They say it reduces the pulses per load. Usually its something like 1000 counts / kwh. Maybe it makes the counts more for an kwh.
???

I'm putting two and two together here and it's sounding like power theft....

A connection is a connection, the device used to make it won't have any effect on the energy consumption or the metering.

These types of connectors are notoriously unreliable, I wouldn't touch them with a barge pole for any connection that's more than a couple of Amps. I've never seen them used by the council in my area, only the split bolt line-tap connectors.