The DRM Chair has only a limited number of use before it self-destructs. The number of use was set to 8, so everyone could sit down and enjoy a single time the chair. A small sensor detects when someone sits and decrements a counter.
Every time someone sits up, the chair knocks a number of time to signal how many uses are left. When reaching zero, the self-destruct system is turned on and the structural joints of the chair are melted.