Not to be too critical, but many of the thefts listed on this forum seem to be because people are behaving a bit stupidly. Leaving passports in jackets in a bar would seem to fall under the same heading.

Protect your property. Beware of "friendly" strangers, and be cognizant of the opportunity that crowded places offer to pickpockets.

In general, I try not to be in very crowded places, or if I am, have my hand over my shirt pocket where my money is. And of course, don't take out more stuff than you need. When I'm traveling, I'll keep my money and valuables in the safe, and just take out what I need for that day. So, if I'm robbed, I lose a 2 year old digital camera, and maybe $50-$100.