In the Philippines, Pick pockets like to slice the rear pockets if they see something bulging like a wallet. My wife, who grew up and lived there until her mid-30's always reminds me to keep my wallet inside my front pocket.

When in a foreign country, I always have a separate wallet with all my US Cards, money, etc. and keep it locked up/hidden in my hotel while I'll use another wallet with a copy of my info page of my US passport and just enough local currency to be able buy/do what I am doing for that outing. I will keep that in my front pocket as there have been times I have been bumped into while walking around.

If I am held up, they won't get much. If I am pickpocketed, they won't get anything except maybe some sticky stuff I may put in the rear pocket that can be washed out with the laundry.