1) IP bans don't work because folks can easily change their IP address.
2) MAC address bans don't work because folks can also change their MAC address. In addition, the MAC address for your machine is only included in local packets ... as soon as the traffic hits a router/modem ... your machine MAC address is not included in the data packet. PGI could add code to the client to pull out "unique" hardware identifiers from the machine and then pass that information along to their servers but this could be a privacy issue and would probably require revisions to the EULA.
However, there are other reasons that neither of these are effective ... IP addresses can apply to entire subnets when NAT is involved ... so an entire University residence for example has the same IP address from the outside. Finally, multiple people can use one set of hardware ... banning the hardware, if it can be uniquely identified will ban anyone who sits down at that machine to play whether they are guilty or not.
Edited by Mawai, 20 March 2015 - 11:00 AM.