SCP-159 - Perfect Lockdown

Item #: SCP-159 Object Class: Safe Special Containment Procedures: SCP-159 is currently stored in a locked locker at Site-██. Knowledge of SCP-159 is restricted to personnel of Level 3 or higher; access is permitted only to personnel of Level 4 or higher. Use of SCP-159 is forbidden unless circumstances necessitate it. Should SCP-159 be deemed necessary to prevent a catastrophic scenario, O5 is authorized to order the immediate deployment of SCP-159 to the required location. Description: SCP-159 appears as a standard neon sign, displaying the word "OPEN" in a style similar to those commonly found in small shops. When SCP-159 is displayed externally through a building's window and deactivated by unplugging it from its power source1, the building becomes impossible to enter by any means. The lockdown effect ceases immediately upon SCP-159 being reconnected to a power source. If the switch is turned to "OFF" before SCP-159 is unplugged, the lockdown effect will not occur. Source: http://scpwiki.com/scp-159 CC-BY-SA licensed.