In an interview with ABC's "Good Morning America," U.S. Attorney General Eric Holder spoke of the ongoing fight to protect American national security and expressed his growing concern with the threat of homegrown terror - a danger which he said "keeps me up at night."
"What I am trying to do in this interview is to make people aware of the fact that the threat is real, the threat is different, the threat is constant," Holder told ABC's Pierre Thomas, in an interview that aired Tuesday morning.
"The threat has changed from simply worrying about foreigners coming here, to worrying about people in the United States, American citizens -- raised here, born here, and who for whatever reason, have decided that they are going to become radicalized and take up arms against the nation in which they were born," Holder added.
The attorney general said that of 126 people who have been charged with allegations related to terrorism in the past 24 months, 50 had been American citizens.
"It is one of the things that keeps me up at night," Holder said. "You didn't worry about this even two years ago -- about individuals, about Americans, to the extent that we now do. And -- that is of -- of great concern."
Holder noted that while he was confident in the United States' counter-terrorism efforts, Americans "have to be prepared for potentially bad news."
"The terrorists only have to be successful once," he said.
Holder pointed to Anwar Al Awlaki, a radical Islamic cleric and dual U.S.-Yemeni citizen, as so dangerous as to be considered among the ranks of Osama bin Laden.
"He would be on the same list with bin Laden," Holder said of Al Awlaki. "He's up there. I don't know whether he's one, two, three, four -- I don't know. But he's certainly on the list of the people who worry me the most."
As a U.S. citizen, Holder said, Awlaki possesses a degree of familiarity with American culture that most foreign terrorists lack. And he has been a common link, Holder says, among many American-bred converts to al Qaeda-tied groups.
"He's an extremely dangerous man," Holder said. "He has shown a desire to harm the United States, a desire to strike the homeland of the United States... He is a person who -- as an American citizen -- is familiar with this country and he brings a dimension, because of that American familiarity, that others do not."
"The ability to go into your basement, turn on your computer, find a site that has this kind of hatred spewed ... they have an ability to take somebody who is perhaps just interested, perhaps just on the edge, and take them over to the other side," Holder added of Awlaki and his associates' ability to reach potential converts through the Internet.
Holder dismissed criticism of recent FBI sting operations, which some have argued employed the use of illegal "entrapment," offering that "options are always given all along the way for them to say, 'You know what, I have changed my mind. I don't want to do it.'"
"I have to have all those tools available to me to try to keep the American people safe, and to do the job that I'm supposed to do as a 21st century attorney general," Holder said. "We are doing everything that we possibly can to keep the American people safe...We are vigilant, we are doing everything we can to keep our homeland secure."
When asked about WikiLeaks and the potential prosecution of Julian Assange, Holder said, "it's an ongoing investigation."
"What Wikileaks did, at the end of the day, was harmful to American security, put American agents and properties ... at risk ... and I think for arrogant and misguided reasons," he said.
Lucy Madison is a political reporter for CBSNews.com. You can read more of her posts here. Follow Hotsheet on Facebook and Twitter.