Steel coil tether for your phone

This will deter most thieves from going after your phone.  A strong steel coil attached to your phone on one end and the other to your belt loop or backpack. They can't grab it, cut it, or get away quickly. Place the phone tab between your case and the phone with the clip extending out of the bottom hole.  Attach one end of the steel coil to your phone and the other to your person. Phone can be accessed easily and won't get snatched or accidentally dropped.

Police in European cities are very aware of these phone thieves and how they target tourists.  They look for easy targets and will instantly see your phone is connected to your body—the deterrent you need to keep them away.