When I worked at O2 it was drummed into advisers that callers would not be given access to their accounts until strict security protocols where satisfied.
If access was denied and the customer became abusive we could a)terminate the call or b) pass the call to a manager , which was part of the manager's job. You are also lucky if a manager or team coach deem it part of his job to actually speak to people nowadays!
Oh how times have changed. I believe that many staff have been allowed to leave the company under the cost cutting policies adapted by many private and national companies. These have been replaced largely by agency staff obviously on a much lower wage than the staff leaving and without the benefits of other company employees.
Obviously these employees will still have to undergo strict training in procedures and sign the Data Protection Act.
Just saying, it's the way most of these telecom companies are going now.