Chris Ofili's work "The Holy Virgin Mary" was part of the "Sensation" exhibit in New York in 1999. The work shows an African Virgin Mary covered with elephant dung. New York City Mayor Rudolph Giuliani said the painting was offensive and filed suit to get the museum's lease revoked after it refused to remove the painting. A federal judge sided with the museum.

This sculpture titled "Self," by the artist Marc Quinn, is kept in a refrigerated container because it is made of the artist's frozen blood.

"Madame X" by American artist John Singer Sargent caused a scandal when it was shown in Paris in 1884. Sargent was accused of painting the woman in a sexually suggestive pose.

Renee Cox posed nude as Jesus for her work "Yo Mama's Last Supper." When it was included in an exhibit at the Brooklyn Museum of Art in 2001, New York Mayor Rudolph Giuliani called for "decency standards" for artworks at publicly funded museums.

Garden gnomes with their right arms raised in a Hitler salute are the work of German artist Ottmar Hoerl, who installed them as part of an exhibition in the main square of Straubing, Germany, in October 2009. The exhibit was highly controversial because Nazi salutes and symbols have been illegal in Germany since the end of World War II.

The "Kill Your Politician" exhibit, staged at a gallery in Prague, Czech Republic, in April 2009, included portraits of all 200 members of the Czech Chamber of Deputies. Viewers were allowed to shoot the politicians they disliked.

An art installation called "Old Persons Home" by Chinese artists Sun Yuan and Peng Yu includes figures dressed like world leaders sitting in electric wheelchairs that roll around, randomly hitting each other. The artists are known for using materials such as human fat in their works.

"Western Christian Civilization," by Argentine artist Leon Ferrari, shows Christ mounted on an American fighter jet.

Artist Al Greenall takes delivery of one of the 100 model pigs that were placed on the streets of Bath, England, for six months in 2008 as part of a project to commemorate the city's founding father who, according to legend, discovered its healing springs with his herd of pigs 3,000 years ago. Some officials objected to the exhibit, saying it trivialized Bath's historic locations and harmed its status as a World Heritage City.

"Body Worlds," by German scientist Gunther von Hagens, is comprised of "plastinated" human bodies. Von Hagens, who developed the preservation technique, says the exhibit is meant to teach people about the skeletal and cardiovascular systems and the treatment of diseases.

"There Will Be No Miracles Here" by Nathan Coley was nominated for the 2007 Turner Prize, which honors the achievements of an outstanding artist living and working in Britain.

A marble sculpture by British artist Marc Quinn titled "Alison Lapper Pregnant" was displayed in Trafalgar Square in London in September 2005. The statue portrayed Lapper, a disabled artist, naked and eight months pregnant.

The painting "Heuler" is part of Jorg Immendorff's "Cafe Deutschland" series of paintings. Immendorff, who died of ALS in 2007, was considered one of Germany's most controversial contemporary artists, partly due to his left-wing political ideas. Much of his work depicted the conflict between East Germany and West Germany before the Berlin Wall came down.

"Love's Paradox" by Damien Hirst is part of the installation "Beyond Belief," which includes dead animals. Here, cows are bisected and preserved in formaldehyde. The exhibit explores themes of existence, including love and immortality.

A work by Richard Serra, "Stop Bush 2004," shows a prisoner at the notorious Abu Ghraib prison in Iraq.

Andres Serrano's "Piss Christ" shows Jesus in a glass of Serrano's urine. When it was first exhibited in 1989, it caused outrage, partly because it was supported by the National Endowment for the Arts. Serrano's supporters said artistic freedom was at stake.