Protestors claim the group has ties to terrorism. Organizers deny that.
The Islamic conference about the ills of capitalism drew the ire of those in protest.
"It is banned in Germany. They tried to ban it in Britain. They couldn't here. That's why they can come here with impunity and talk down about America," said protestor Dan Rivers.
The Chicago chapter of the international Hizb Ut-Tahir did not allow ABC7 Chicago's cameras to attend Saturday's 'Khilafah Conference 2009.'
Under the "Fall of Capitalism and Rise of Islam" theme, lectures were given addressing the distribution of wealth in Islam.
Despite that, some attendees said the conference was not anti-American.
"It's only the media and some other people, conservatives, who make up the idea that all Muslims are terrorists," conference participant Farid Conyers said.
Hizb-Ut-Tahrir has been around since the early 1950s. Organizers of the conference say theirs is a non-violent political and ideological group that denounces capitalism and promotes an Islamic nation state in the Muslim world.
"This is part of our culture. This is what we teach. This is what we train our people conduct ourselves," said the organization's Muhammad Malkawi.
The founder of Washington, D.C.-based peace group Responsible for Equality And Liberty (REAL) says the Islamic group promotes hate.
"They can publicly recruit individuals to be against democracy and freedom," said REAL's Jeff Imm.
Sunday's gathering drew plenty of extra security and curiosity, as organizers said they were the victims of misinformation and negative stereotypes. They also deny any support of terrorists.
"They said one of the masterminds of 9/11 was a member and linked to the group. Absolutely baseless. Absolutely not," said Malkawi.
The Jewish Federation of Metropolitan Chicago has issued a statement, "The group's ideology is hostile to capitalism and other notions of Western liberalism."
Members of the Hizb-Ut-Tahrir group want a caliphate, which is a unified Islamic doctrine under which a worldwide Muslim leader is held accountable. Critics say the fringe group's teachings are not based in authentic Islamic doctrine.
"The proper response to a group like this is to debunk their philosophy," said Ahmed Rehab of the Council on American-Islamic Relations.
Conference organizers claimed to have approximately 700 participants throughout the day. The event's venue, the Oak Lawn Hilton, was not the original host of Sunday's conference. A Muslim school in Bridgeview retracted its invitation after school officials say the group misrepresented its intentions.
Hizb-Ut-Tahrir refutes that, saying the school knew all along.