[the8472]

Adding a data bus to all lines would be a much bigger deal than changing sockets for existing lines or running a slightly different voltage (often within tolerance of the power supplies anyway!) over the same wires.

And USB isn't meant to operate over those long distances. So you'd either need some active component in each socket or devise a new standard.

[ajuc]

It doesn't have to be usb, maybe ethernet would work? Or something new if needed.

Rewiring might be a problem (but it was the same with adding a ground wire).

If we have to we can do the data-over-power between the sockets, and use data lines from sockets to devices.

This would ensure devices don't have to adapt to that hack and eventually we'll have a clean solution.