http://www.mediaartnet.org/works/following-piece/

Vito Acconci
Vito Acconci, «Following Piece», 1969
«Following Piece» is one of Acconci's early works. The underlying idea was to select a person from the passers-by who were by chance walking by and to follow the person until he or she disappeared into a private place where Acconci could not enter. The act of following could last a few minutes, if the person then got into a car, or four or five hours, if the person went to a cinema or restaurant. Acconci carried out this performance everyday for a month. And he typed up an account of each pursuit, sending it each time to a different member of the art community.