The chairman of a key congressional committee is scheduled this week to examine the apparent threat posed by homegrown Islamic radicals.
But some members of the Muslim community fear that Rep. Peter King, R-N.Y., is on a witch hunt, holding hearings that recall the days of Joseph McCarthy's anti-Communism crusade.
Hundreds of people in New York City this weekend protested the hearing entitled "Radicalization in the American Muslim community," which is scheduled for Thursday.
"Peter King, we are on to your game, dividing people and using fear and intolerance," one female protester said.
Rep. Keith Ellison, D-Minn., the first Muslim elected to Congress who will be testify at the hearing, said, "These hearings, as presently organized, won't do any good. And they may well do a lot of damage."
Ibrahim Hooper, national communications director for the Council on American-Islamic Relations, said, "These hearings have the potential to demonize Islam."
But King has said the goal of the House Committee on Homeland Security is not to target all Muslims but to deal with the reality of terrorism.
Forty-nine suspects have been charged with acts of international terrorism in the past two years. They are nearly all Muslim men, typically in their 20 or 30s.
The charges include plotting to blow up a car in Times Square, targeting the New York City subway and the shooting spree at Fort Hood, Texas.
And there have been numerous stings, including one involving New York City men who allegedly wanted to use a shoulder-fired missile to shoot down U.S. military planes.
Other stings involved young men radicalized on the Internet.
Muslims Charge Intolerance
The members of the Muslim community believe it is being unfairly maligned because of the actions of a few.
And Muslim leaders have pointed out that a number of terrorism suspects were arrested based on tips from their community.
Some feel besieged and point to last year's stabbing of a New York Muslim cab driver and the controversy surrounding the scheduled burning of the Koran as recent examples of intolerance.
And a protest last week outside a fundraiser for Muslim charities in Orange County, Calif. turned ugly.
"Mohammad was a pervert, Mohammad was a child molester, Mohammad was a pervert, " a protester said as people left the event.
Others chimed in, screaming at the Muslim participants: "You beat your women and you rape your children. Why don't you go and beat your wife like you do every night?"
And while the threat is real, the Obama administration has taken great pains to make clear that its fight is against extremists, not Islam.
"In the United States," deputy national security director Dennis McDonough said, "we do not practice guilt by association."