The Polish government-in-exile in London first reported the gassing of prisoners in Auschwitz on 21 July 1942, and reported the gassing of Soviet POWs and Jews on 4 September 1942. In 1943, the Kampfgruppe Auschwitz (Combat Group Auschwitz) was organized within the camp with the aim of sending out information about what was happening. Sonderkommandos buried notes in the ground, hoping they would be found by the camp's liberators. The group also smuggled out photographs; the Sonderkommando photographs, of events around the gas chambers in Auschwitz II, were smuggled out of the camp in September 1944 in a toothpaste tube. According to Fleming, the British press responded, in 1943 and the first half of 1944, either by not publishing reports about Auschwitz or by burying them on the inside pages. The exception was the Polish Jewish Observer, published as a supplement to the City and East London Observer and edited by Joel Cang, a former Warsaw correspondent for the Manchester Guardian. The British reticence stemmed from a Foreign Office concern that the public might pressure the government to respond or provide refuge for the Jews, and that British actions on behalf of the Jews might affect its relationships in the Middle East. There was similar reticence in the United States, and indeed within the Polish government-in-exile and the Polish resistance. According to Fleming, the scholarship suggests that the Polish resistance distributed information about the Holocaust in Auschwitz without challenging the Allies' reluctance to highlight it.
After the war, laws were made in Germany and other countries, especially countries in Europe, that make it illegal to say the Holocaust never happened. Sometimes they also ban questioning the number of people affected by it, which is saying that not so many people were killed as most people think. There has been some controversy over whether this affects people's free speech. Certain countries, such as Germany, Austria, and France also ban the use of Nazi symbols to stop Nazis from using them.
Use of the word "concentration" came from the idea of confining people in one place because they belong to a group that is considered undesirable in some way. The term itself originated in 1897 when the "reconcentration camps" were set up in Cuba by General Valeriano Weyler. In the past, the U.S. government had used concentration camps against Native Americans and the British had also used them during the Second Boer War. Between 1904 and 1908, the Schutztruppe of the Imperial German Army operated concentration camps in German South-West Africa (now Namibia) as part of its genocide of the Herero and Namaqua peoples. The Shark Island Concentration Camp in Lüderitz was the largest camp and the one with the harshest conditions.