Not very good idea me thinks. Anyways a few weeks back in Damansara Perdana, a friend of mine witness first hand 2 guys grab a notebook backpack and run away in a motorbike in broad daylight. The incident happened in a mamak restaurant with many people. The owner give chase but to no sucess. Bystanders also try to help but most was like in shock or something.

So if it happens to you, just your bad luck.