Do you lock your backpack?

I travel only with a backpack, and have never locked it. Ever. Nor have a ever been bothered about it because if I lose anything it will be some clothes and perhaps a pair of shoes, no big deal. Besides, my backpack has 3 zips — I refuse to have 3 locks and keys; and a chord that you have to draw to close the biggest opening of my backpack on the top, I don’t think it’s even possible to lock that.

Perhaps it’s irresponsible and I’ve been lucky to never have been robbed. But, funnily enough, I don’t know anybody who locks their backpack!I came across this article on different/innovative/cheap ways to lock your backpack, and it made me wonder whether I should start using locks. Not to prevent theft but perhaps more to prevent the possibility of people putting illegal things in my bag (e.g. drugs?).

Do you lock your backpack? If so, how? Have you ever been robbed or cheated because you didn’t lock it?