Islamic organizations say the government is unfairly singling them out.
In this Intelligence Report: Why Chicago is at the epicenter of the argument.
The counter-terrorism squad at the FBI in Chicago and the terrorism prosecution unit in the U.S. attorney's office in Chicago currently have dozens of open investigations, nearly all of them involving radical Muslim suspects linked to overseas terror groups. Those cases currently in federal court have put Chicago on the radar at the center of Muslim extremist prosecutions in the U.S. and at the heart of the discussion this week on Capitol Hill.
"As chairman of the Homeland Security Committee, I don't see I have any choice," said Rep. Peter King, (R) New York. "I have to investigate, No. 1, How extensive is the radicalization? How is it done? What are the signs of radicalization? And is the leadership of the Muslim community cooperating with law enforcement?"
When Congressman King convenes the hearing on Thursday, the case of Chicagoan David Coleman Headley will be the most significant example of Muslim radicalization.
Headley was recruited by Muslim extremists in Pakistan and helped plot the deadly 2008 attack on Mumbai, India. He has pleaded guilty to recruiting Chicago businessman Tahawwur Rana to help in the plot. Rana is going on trial May 16.
They are among a half-dozen American defendants charged right now in Chicago cases as radical Islamists.
Congressman King says his hearing will help U.S. intelligence agencies determine how terrorist groups are going into the nation's mosques to recruit young Muslims.
Even before the hearing has been held, King irritated U.S. Muslims by stating that 80 percent of American mosques are controlled by radical imams.
In New York, protesters are already taking aim at King, including the imam from the Ground Zero mosque controversy. Imam Feisal Abdul Rauf says he believes the hearing creates a perception that vilifies the Muslim community in the United States.
"The real enemy is not Islam and Muslims, the real enemy is radicalization and extremism," the imam said.
"What I want to do now is not to go down the same road as McCarthyism, not to target a whole community with the fault of the actions of a few," said celebrity protester Russell Simmons.
Protesters say they fear this week's hearing will increase anti-Muslim outrage, such as at an encounter three weeks in Southern California when hundreds accosted speakers at an Islamic fundraiser and accused them of being radicals.
In a pre-emptive strike, the Council on American-Islamic Relations will hold a news conference in Washington on Wednesday, the day before the hearing starts. CAIR intend leaders to challenge what they believe will be misinformation presented by members of Congress at the Homeland Security Committee hearing.
Republican Congressman Joe Walsh from Fox Lake is on the committee along with Democrat Danny Davis from Chicago.