Justin Bieber's 'Purpose' graffiti under investigation

San Francisco's city attorney is demanding that Justin Bieber's music publisher help determine who is responsible for sidewalk graffiti promoting the pop star's latest album.
City attorney Dennis Herrera sent a letter to Universal Music Group earlier this week, saying the graffiti appears to have been applied with spray paint that has not come off even after recent rainstorms, reported Billboard.
That contrasts with other recent sidewalk marketing campaigns that have used chalk, according to Herrera.
Herrera said public works crews have removed some of the graffiti at great expense, although he did not provide a figure. The city attorney's office released photographs of eight instances of the graffiti and asked for Universal's help in determining its full scope.

Emails seeking comment from representatives of Universal Music Group were not immediately returned.
The graffiti promoting Bieber's new album, Purpose, has been found in Haight-Ashbury and other neighborhoods. City officials have received complaints about it, Herrera said.