Push, Push Pass.

[highwayman]

What I want to know is...Why do the banks keep the vault doors open all day, but chain the pens to the counter tops?!?

Because the place is well protected, there are regular Brinks runs through out the day, and also when the cash reaches a certain amount

As for the pens, without a chain they roll off the counter and need someone to routinely pick them up, and nobody likes to do that.
Also because customers "accidently" walk out with them in their pockets. ;)