Bala,
I wrote
this about a year ago; I think the advice still applies. I think it is also relatively easy to understand.
Locking-down your drive is an option. You can also put it in a locked drawer (with wires running through the back) or in a closet, if you feel the need; I do not.
When people talk about taking their data home daily, I always quote
this event because of its irony. There are innumerable stories like it.