PAC Codes
How about preventing networks using the PAC code as bloody sales tool and holding you to ransom for it as means of keeping you when you have already made your mind up. That would be useful. I've spent an hour on the phone with some networks retentions team to no end because whilst I'm interested in staying they really can't offer me anything better than they do new customers. GiffGaff just give you the PAC on their site, no messing about. That's how it should be.