communications company, and Comverse Infosys, another Israeli-run company that provides electronic eavesdropping technology for the U.S. government. Israeli agents It has been claimed that Israeli agents may have had foreknowledge of the attacks, and a persistent theory claimed Israeli and/or Jewish involvement. Four hours after the attack, the FBI arrested five Israelis who had been filming the smoking skyline from the roof of a white van in the parking lot of an apartment building, for "puzzling behavior." The Israelis were videotaping the events, and one bystander said they acted in a suspicious manner: "They were like happy, you know ... They didn't look shocked to me. I thought it was very strange." The van was found to be owned by an Israeli-owned company called Urban Moving, which the FBI believed was providing cover for an Israeli intelligence operation. The case was then moved to the FBI's Foreign Counterintelligence Section. According to a former CIA operations chief, "many people in the U.S. intelligence community believed that some of the men arrested were working for Israeli intelligence." A spokesperson for the Israeli Embassy in the United States said the men had not been involved in any intelligence operation in the United States. The FBI eventually concluded that the five Israelis probably had no foreknowledge of the attacks. World Trade Center The plane crashes and resulting fires caused the collapse of the World Trade Center. Controlled demolition conspiracy theories say the collapse of the North Tower, South Tower, or of 7 World Trade Center was caused by explosives installed in the buildings in advance. Demolition theory proponents, such as Brigham Young University physicist Steven E. Jones, architect Richard Gage, software engineer Jim Hoffman, and theologian David Ray Griffin, argue that the aircraft impacts and resulting fires could not have weakened the buildings sufficiently to initiate a catastrophic collapse, and that the buildings would not have collapsed completely, nor at the speeds that they did, without additional factors weakening the structures. In the article "Active Thermotic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe", which appeared in the Open Chemical Physics Journal, authors Niels Harrit of the University of Copenhagen's Department of Chemistry, Jeffrey Farrer of Brigham Young University's Department of Physics and Astronomy, Steven E. Jones, and others state that thermite and nano-thermite composites in the dust and debris were found following the collapse of the three buildings. The article