Our group got pickpocketed at a concert of the weekend

1. I think it's the worst when your phone gets stolen. I think if there's a feature (at least for iphones) where you need a password to turn off your phone, then if you're at a concert, you'll probably be able to turn on 'find my iphone' before the thief reaches out of your grasp. I think for Android you should find a phone that is hard to take the battery out or else they can turn off your phone that way.

2. If it's your wallet or 'stuff', I think something like Tile would be a great tool to track your stuff. It runs on low energy bluetooth so you'll only have to replace it once a year. And also the app has this cool radar tracking feature.

In such a situation there was a lot of people, there was only a second or two to know who took it and then it was gone. My girlfriends cousin had her cell phone in a fanny pack (zipped). Someone still unzipped it and took it.