Lockdowns are arrestable actions where protestors place themselves with devices which makes it difficult to remove them quickly without causing physical harm to the protestor. The presence of the protestor may prevent roadways, gates, doors, or equipment from being used. Typically the protestor is able to release themselves from the devices, although not always- as in the case of those utilizing bicycle U-locks. Devices known as lockboxes are purpose-built and designed so that the user(s) can unlock themselves and can be reinforced with a wide variety of materials, however the user(s) will not be able to use either of their hands in the meanwhile.