Justin Bieber graffiti is part of a widespread and illegal “guerrilla marketing” campaign in San Francsico to promote the Nov. 13 release of the pop star’s new album, “Purpose.” This example—photographed on Dec. 26 at 1083 Howard Street—persists several weeks and multiple rainstorms after it was first applied, much to the irritation of City residents and officials. (Photo: San Francisco City Attorney’s office)

Justin Bieber graffiti is part of a widespread and illegal “guerrilla marketing” campaign in San Francsico to promote the Nov. 13 release of the pop star’s new album, “Purpose.” This example—photographed on Dec. 26 at 1083 Howard Street—persists several weeks and multiple rainstorms after it was first applied, much to the irritation of City residents and officials. (Photo: San Francisco City Attorney’s office)

Justin Bieber graffiti is part of a widespread and illegal “guerrilla marketing” campaign in San Francsico to promote the Nov. 13 release of the pop star’s new album, “Purpose.” This example—photographed on Dec. 26 at 1083 Howard Street—persists several weeks and multiple rainstorms after it was first applied, much to the irritation of City residents and officials. (Photo: San Francisco City Attorney’s office)