Polish artist Zbigniew Libera's Konzentrationslager is a work of art he created in 1996 with the unwitting help of the Lego Group, who were happy to help out with a few buckets of bricks until they realized that Libera's project consisted of fake Lego packaging detailing an Auschwitz-style death camp.
From the Cult of Lego:
From the beginning, Konzentrationslager caused a huge sensation, with viewers split on whether it was an important work or a travesty. Depicting genocide with a toy made people uncomfortable. Some Holocaust activists saw the work as trivializing the experiences of survivors, while others disagreed. The Jewish Museum in New York City displayed the sets for several months in 2002 as part of an exhibit on Nazi imagery in modern art.
Even LEGO joined in the criticism, complaining that Libera hadn't told the company what he was intending when it donated the bricks and that this contribution didn't constitute sponsorship as implied by the packaging’s labeling. LEGO tried to get Libera to stop displaying the work, backing down from its pressure only after the artist hired a lawyer.
Libera, one of Poland's preeminent artists, was asked to attend the Venice Biennale in 1997 -- on the condition that he leave Konzentrationslager at home. The artist had been imprisoned in the early '80s for publishing an underground comic mocking Poland's Soviet rulers, and that kind of put him off of censorship, so he chose not to attend.
Images Courtesy of Raster Gallery, Warsaw