Lockpick "The skill of opening locks without the proper key. The use of lock picks or electronic lock picks will greatly enhance this skill."
You can not only lockpick closed chests and doors, but also highjack some cars. In order to do so, use your skill on the car and wait for the timer to end (30s.)
Also there is a possibility to both set (not implemented) and brake electronic locks. In order to brake an electronic lock, you will need an advanced electronic lockpick and a high level of skill.
You will start with 10%+(PE+AG) %of this skill.