The Department of Justice is asking a federal court to bar three Philadelphia-area tax preparers from preparing federal tax returns for others. The government seeks to block Deron Joe, Edmund Dassin and James Tokpawhiea, Liberian nationals who are legal permanent residents of the United States, from engaging in the tax preparation business. The suit alleges that most customers of their business, Urban Tax Professionals, are also from Liberia and were referred by friends and relatives.