According to Wikipedia, “Lock On is a style of street art, where artists create installations by attaching sculptures to public furniture using lengths of chain and old bike locks. The sculptures are often arranged to give the impression that they are interacting with surroundings.”
One of the most well-known street artists doing Lock-on is Tejn, located in Copenhagen. Sort of a 3D Banksy in metal. IMO Lock-on sculpture is even more compelling than graffiti and other two-dimensional street art, since it is “touchable”.
This reminds me of another form of Lock-on: the ghost bike as a memorial to cyclists killed in car-bike collisions. Very effective and poignant. RIP good friend Dave (former musician, father of 2 teenage girls).
Photo copyright of Artinpublicplaces.