break-in. On 31 May 1988, all three paintings were recovered undamaged by police pretending to be buyers. The thief was arrested and convicted. On 15 May 2011, AFC Ajax's victory in the national competition was celebrated at the Museum Square. During the celebration, supporters damaged the Benthem Crouwel Wing's rooftop and glass panels, resulting in €400,000 of damage and prompting a change in venue to the Amsterdam Arena for the celebration of AFC Ajax's subsequent 2012 victory. Despite these issues, the city government of Amsterdam has stated that it will still consider using the Museum Square as a potential location for large events. Collection The museum collection holds almost 90,000 objects, collected since 1874. With important clusters and cores focusing on De Stijl, Bauhaus, Pop Art and CoBrA and, more recently, Neo-Impressionism, the collection represents virtually every significant movement in art and design of the 20th and 21st centuries. The Stedelijk also has a comprehensive collection of drawings and paintings by Kazimir Malevich. Key pieces by Post-Impressionists Paul Cézanne and Vincent van Gogh exemplify art from the late 19th century. The collection is sub-divided into the following disciplines: Painting Sculpture Installation Moving image and sound Prints and drawings Posters Photography Graphic design Industrial design Artist books Lucebert archive In early 2010, the Stedelijk Museum partnered up with design agency Fabrique and augmented reality firm Layar to develop virtual art tours called "ARtours". Using smartphone technology, visitors are treated to additional stories and images about the collection both inside the museum and outside around the city. In the final phase of this project at the end of 2011, the public was invited to add their own stories, images, and other information through the open source platform. In 2018, a mural created by Keith Haring in 1986 on the Stedelijk Museum's storage facility was revealed after being covered by sheets of aluminum a few years after its completion. The 40-foot-mural is the artist's largest public work and was created for his first solo museum exhibition. Digitization In November 2009, the museum started a project to digitize the historical archive, which spans from 1895 to 1980. The archive contains around 1.5 million documents in around 7,000 folders, and includes correspondence letters of the director and buyer records. Ownership of the documents has been officially transferred to the Amsterdam City Archive, but the documents will remain in the Stedelijk Museum until the digitization project