Sixteen European countries and Israel have laws against Holocaust denial, the denial of the systematic genocidal killing of approximately six million Jews in Europe by Nazi Germany in the 1930s and 1940s. Many countries also have broader laws that criminalize genocide denial. Of the countries that ban Holocaust denial, some, such as Austria, Germany, Hungary, and Romania, were among the perpetrators of the Holocaust, and many of these also ban other elements associated with Nazism, such as the display of Nazi symbols.