During investigations that led to the June 16 indictments in the terrorism-related case of Hamid Hayat and his father in Lodi, Calif., authorities also arrested leaders of the Lodi mosque the Hayats attended. Imam Shabbir Ahmed and former imam Mohammad Adil Khan were arrested June 6 on immigration violations. Ahmed's 19-year-old son was arrested on the same charges. On June 17, Jordanian citizen Yaser Issa, a prominent imam of the Muslim community in El Paso, Texas, was arrested for visa violations, though authorities have outlined no specific security concern as it relates to Issa. The arrest has caused indignation in El Paso's Muslim community. Law enforcement authorities often use suspicion of visa fraud and other immigration violations as reasons to investigate and prosecute suspects who could be planning — or encouraging — strikes within the United States. In most cases, arresting suspects on immigration violations is an expeditious way to deport them — and thus disrupt potential attacks before they can be carried out. In some cases, law enforcement lacks sufficient evidence to arrest suspects for plotting attacks, but authorities can investigate them for immigration violations. In the course of the investigation, a search warrant can be obtained for the suspect's home or business, where incriminating evidence or vital tactical intelligence can be found that positively links the suspect to a terrorist plot. At other times, the visa violation is a backup in case the more serious charge falls through. A prime example of this is the case of Egyptian cleric Omar Abdel-Rahman, known as the "Blind Sheikh." Authorities arrested Abdel-Rahman on charges of seditious conspiracy in connection with the 1993 World Trade Center bombing. However, had they been unable to get the conspiracy conviction, the authorities were ready to prosecute Abdel-Rahman for visa fraud, an easier charge to successfully prosecute. In February 2003, U.S. Immigration and Naturalization Service agents arrested Ernst Zundel at his home in Pigeon Forge, Tenn., for alleged immigration violations. Zundel, a prominent anti-Semite and Holocaust denier, allegedly distributed neo-Nazi paraphernalia and propaganda and encouraged neo-Nazis to commit acts of violence against Jews and other minorities in the United States. Zundel, who had arrived in the United States from Canada, was deported back to Canada after being held in U.S. custody for two weeks. Considering him a threat to national security, the Canadians subsequently deported him back to Germany, where he faces charges of inciting racial hatred and defaming the memory of the dead. Many al Qaeda operation manuals encourage using fraudulent documents as a way of entering a country illegally or of continuing to stay in a country after a legitimate visa has expired. After his February 1995 arrest in Pakistan, Abdel Basit, the alleged mastermind of the 1993 World Trade Center attack, used 14 aliases. In fact, he usually is referred to as Ramzi Yousef, one of the names he used on a forged passport. With more scrutiny applied to immigrants and tourists in the post-Sept.11 environment, using forged passports or visas has become even more necessary if jihadists are to successfully enter the United States. Because of this, however, immigration violations often are the Achilles heel of terrorist cells. Immigration-related document fraud and financial fraud often go hand in glove. In fact, document fraud often is committed to facilitate financial fraud, which is one way potential terrorists gather money to carry out their operations. It is rare today to read a news article about terrorist suspects in the United States or Europe in which fraudulent immigration documents and financial fraud are not mentioned. Investigations into immigration-related document fraud allow law enforcement to disrupt a cell before it can carry out a planned attack. Furthermore, charges in these cases provide the legal means to deport potentially dangerous individuals — those who are planning attacks as well as those who encourage them.