What is tin foil on door knob?

Tin foil on a door knob is often used as a makeshift lock pick. When wrapped around the end of a thin tool such as a paperclip or bobby pin, the foil can be used to manipulate the locking mechanism of the door. It is an effective technique used by both locksmiths and criminals alike. However, using this method to gain unauthorized access to a locked door is illegal and can result in criminal charges. Additionally, using tin foil on a door knob may damage the finish or paint of the door knob.