*Various [[9/11 conspiracy theories]]. People who embrace these are called [[Truther]]s. The theories generally state that the World Trade Center buildings were not brought down by airplane collisions, but (typically) by detonation of explosives planted earlier.<ref>They claim that Jewish workers had been telephoned in advance and told not to come to work (false), that airplane collisions would have caused the buildings to topple over rather than collapse directly downward (false, ignorant of high-school physics), or that the heat of burning aviation fuel would not raise the temperature sufficiently to melt the girders (false, the temperature to make iron visibly bend is much higher than the temperature to make it lose the strength needed to hold up a building).</ref> Truthers often ascribe the motivation for this to some kind of nefarious scheme by the [[George W. Bush]] administration. Among the websites promoting these theories are [[Infowars]] and [https://wearechange.org We Are Change].
*The belief that President [[Franklin D. Roosevelt]] knew about the [[Attack on Pearl Harbor]] in advance, and allowed it to happen, so America could get into the war; that officers ignored evidence that the attack had started.<ref>From decrypts of Japanese communications, American intelligence expected a major military operation within that time frame, but believed it would take place in southern Asia.</ref>
*The influence of [[secret societies]], [[fraternal organizations]], and various [[religion|religious groups]]. [[Freemasons]], the [[Illuminati]], the [[United Nations]], the [[Catholic Church]], [[Judaism]], and the Catholic "Society of Jesus" ([[Jesuits]]) are popular targets. Often these groups are accused of being behind so-called "[[shadow government]]s." [[FEMA]] has been accused of being a "shadow government" as well. This These conspiracy theory, and the one preceding, theories have been around since the 1700's. At present, the phrase "[[New World Order]]" is often associated with them.
*The notion that [[Jews]] are [[Anti-Semitism|conspiring to destroy civilization]]. This one is particularly serious. It has been going on in [[Europe]] for hundreds of years. It led to [[Anti-Semitism]], and, more tragically, the [[Holocaust]] of the [[Nazi Party|Nazi]]s in 20<sup>th</sup> century Germany.<ref>[http://newint.org/features/2004/10/01/conspiracism/ "ZOG Ate My Brains"]</ref>
*Denial that the Holocaust happened, and/or claims of exaggeration. In a number of European countries, Holocaust denial is a criminal offense. [[Iran]]ian president [[Mahmoud Ahmadinejad]] is among this theory's supporters.