NEW YORK • Artists and museums are often in the thick of free speech debates - think of former New York mayor Rudolph W. Giuliani's battle with the Brooklyn Museum over a Virgin Mary artwork with elephant dung and, more recently, a fight over an exhibit that evoked Emmett Till's mutilated corpse.
Till was a 14-year-old African-American who was lynched in Mississippi in 1955.
Typically the art world holds its ground. But in two recent controversies, the protesters are winning.
On Monday, the Guggenheim pulled three works from a highly anticipated exhibition after pressure from animal-rights supporters over the show Art And China After 1989: Theatre Of The World.
The Walker Art Centre recently moved to dismantle Sam Durant's sculpture Scaffold - a representation of seven gallows used in historic United States government executions - in response to protests.
Art leaders are concerned that museums are setting worrisome precedents when faced with pressure.
"When an art institution cannot exercise its right for freedom of speech, that is tragic for a modern society," Chinese artist Ai Weiwei said.
"Pressuring museums to pull down artwork shows a narrow understanding about not only animal rights, but also human rights."
The three works in the Guggenheim show, which opens on Oct 6, were created between 1993 and 2003 and intended to depict oppression in China.
One video, Dogs That Cannot Touch Each Other, shows four pairs of pit bulls on non-motorised treadmills, trying to fight even as they struggle to touch.
Another video, A Case Study Of Transference, shows two pigs mating in front of an audience.
And an installation - Theatre Of The World - features hundreds of live crickets, lizards, beetles, snakes and other insects and reptiles under an overhead lamp.
Protesters marched outside the museum over the weekend and an online petition demanded "cruelty-free exhibits" at the Guggenheim.
Guggenheim's spokesman Sarah Eaton said: "The tone in both the petition comments and the social media postings, calls and e-mails was markedly different from what we've seen before and required us to take the threats very seriously."
The Guggenheim has also been a target of protesters in recent years over its decision to build a museum in Abu Dhabi despite concerns about labour practices there.
For many artists and museum professionals, the latest moves at the Guggenheim and Walker amount to an artistic capitulation in the face of heightened political sensitivities amplified by social media.
"Museums are here to show works that are difficult, uncomfortable, provocative," said Mr Tom Eccles, executive director of the Centre For Curatorial Studies at Bard College. "The chilling effect of this... is museums will now look to make exhibitions that won't... offend."
Others say the Guggenheim should have used the controversy to engage the public about difficult art.
But some applauded its decision.
Said Dr Stephen Eisenman, an art history professor at Northwestern University: "The works are cruel and support cruelty and give sanction to animal abuse."
Ms Ingrid Newkirk, president of People for the Ethical Treatment of Animals, commended the withdrawal of "these vile acts of cruelty masked as creativity".
But Dr Sarah Cohen, an art historian at the University at Albany, questioned why the Guggenheim included the works at all.
"The curators do not appear to have considered very deeply the problem of humans forcing certain behaviours in animals," she said.
"Nor did they apparently stop to consider that using pigs as performers to 'inform' human spectators about their cultural hang-ups is a shopworn strategy - as old as dancing bears and the circus."
"In my opinion," she added, "the exploitation of animals to make artistic points is, well, bad art."