I copied this from a response I read. I think this sums it nicely.
The claim here is not that the digital bits on the cable (via the Ethernet frames -> IP frames -> TCP packets) are being altered. The claim, especially in regards to ground loops, is that the ethernet cable is connecting the ground of power going into the switch and the ground of the power going into the device. Thus, you have a system that has “2 grounds”. It is then further claimed that these ground loops, using the hardware given, produce a notable hum or degradation of quality in the D->A conversion, or even later in the chain in analog.
|