Information wants to be free
Part of the issue is the amount of information on each customer that is made available through the portal. It makes sense to have some information available to vodafone workers for customer support (phone model, plan etc), but having absolutely everything on show is just daft.
Home addresses, dates of birth, drivers license numbers (needed to register a sim card to show you're not a terrorist, as terrorists don't drive as everyone knows), voicemail PIN number - it's all available.
The muppets who designed their web portal should be hit with a stick, and told to figure out what resellers, agents, vodafone shop workers etc would realistically need to see to do their jobs, and limit the information available to only that. Giving everyone a full database dump is just asking for trouble, which they've now got.