Pick-pocketing refers to when someone steals items, like your wallet, phone, etc., out of your pocket, bag, etc., and snatching is when someone forcefully snatches away your items from you. Both of these acts are crimes1.
These acts are punishable with jail time of up to 3 years and/or a fine2. If you have experienced pick-pocketing or snatching, read here to understand the steps/options you can take to complain.