At UC Berkeley, photographic images were found over the weekend depicting African Americans who had been lynched.
They were discovered just hours before a demonstration against police brutality organized by a black student union was set to begin.
Late Sunday afternoon, an anonymous group of artists took responsibility for erecting the images, saying the images connected incidents of the past to those of the present.
But many took offense at the action, saying such emotionally-charged images shouldn't be used, even as protest.
Rudolfo Mendoza Denton, a psychology professor at UC Berkeley, said his first concern was about the possibility of violence on campus.
Leigh Raiford, a professor of African American studies, said she understood the reaction of those who felt "traumatized" by the images, but that the images were intended to provoke.
"Confrontational art is not meant to be easy," said Raiford. "The images are really difficult, they are shocking and they are cruel."
But there is a place for such artwork, she said.
"The larger question for me is that these images have been used to intimidate for so long, but they have also been used by black artists and black activists as evidence of crimes and crimes against black people," said Raiford, who is also the author of Imprisoned in a Luminous Glare: Photography and the African American Freedom Struggle (University of North Carolina Press, 2011).
The University called the images "deeply disturbing" and called on the campus to be "vigilant to ensure that we are creating a campus environment that allows for the free exchange of ideas and doesn't frighten or intimidate people."
Claire Holmes, a spokesperson for UC Berkeley, told Take Two that the primary concern for campus police was whether the images were racially motivated. Now that a group has claimed responsibility, it appears that it was an artistic act.
"Art can be disruptive and I think they made their point," said Holmes.