Metastank (1995-1996) is a good example in the Parasite Project, to show how we appropriated the face of the city.
The Metastank was a simple object, a huge bucket in the street with its own postal address.

Of course, the address was not officially approved.Letters reached to the address. On the first day of the project, a postman delivering letters wandered around the bucket as he could not find
their address. He, then, asked the shopkeeper where the address referred. The shopkeeper who knew the project of Metastank answered 'yes, you should put letters into the bucket in the street'.

The postman left the letter as the shopkeeper suggested. As a couple of days passed, delivering letters to the bucket became a regular work for the postman so that the bucket eventually came to have its original
  address. And anybody in the city could open and see in the "METASTANK" and, if some one is interested in the things inside, could take them.