Laptops can contain confidential information, and are inherently less secure than large machines: it is easier to take physical possession of them.
Nationwide building society recently had one stolen that contained customer information; and 3 laptops containing police payroll information were stolen from LogicaCMG, the UK IT services firm.
You have to wonder whether it was absolutely necessary for this information to be on the laptops in the first place. It appears that it may not have been, as Nationwide are saying that the employee who had the laptop stolen may not have been complying with the firm’s security policy. Of course, it’s one thing to have a policy and another for it to be complied with.