There aren't a lot of rebels fighting against the Assad regime in Syria who update Facebook regularly. There are fewer still who were born in Phoenix, Arizona, and are U.S. Army veterans. But that's not why Eric Harroun faces federal charges. The FBI arrested him because he fought alongside Al Qaeda, employing a "weapon of mass destruction."

Harroun — whose last three jobs have been serving in the Army state-side until his discharge following a car accident, working as a mortgage loan officer in Phoenix, and sneaking into Syria to push for the armed overthrow of its leader, in that order — was profiled by Foreign Policy earlier this month, despite the difficulty of having a conversation with him.

Pinning Harroun down is never easy. At times, he appears willing to provide very specific details about himself, while at others he becomes more reserved, preferring to not comment or flat-out denying his previous statements -- only to retract his retractions. He can become inexplicably hostile, hurling accusations of lying and anti-Semitic or anti-Zionist comments, or respond with flippant or jocular comments. He will also, in the middle of a line of questioning, simply write "bye" or "halas" (his rendering of the Arabic word for "enough"), and cease communication.

At the time, the magazine was exploring Harroun's involvement with Jabhat al-Nusra, a group the State Department has identified as being an arm of Al Qaeda. Harroun was reticent to discuss any involvement with the group — at one point, he responded to a question with a flat "5 Amendment" — but Foreign Policy noted his appearance in videos alongside known members of the group.

It appears that Harroun ended up incriminating himself after all. In the FBI's complaint against Harroun, filed today (and visible at the bottom of this article, via Huffington Post), it notes that a magistrate judge authorized a search of Harroun's Facebook page. Through that search, the FBI found comments and posts linking Harroun to the conflict in Syria generally — like the video below, showing Harroun and other fighters looting a downed Syrian helicopter, which also first appeared on his Facebook page.

That video opened a door for the FBI. In a series of interviews with Harroun at an American consulate in Turkey, the FBI probed deeper, eventually getting Harroun to admit to engagement with Jabhat al-Nusra and, more importantly, to the use of a rocket-propelled grenade, something he'd alluded to when describing the helicopter video. RPGs are categorized as a "weapon of mass destruction" by the United States government, and use of such weapons by citizens is illegal, regardless of who's around when it happens. (They also asked him about his statement that "the only good Zionist is a dead Zionist", to which he replied that he "equated Zionism with Nazism and Fascism.")

The Washington Post reports that Harroun flew back to Washington, D.C., yesterday and was arrested on his arrival. Which also means that he'll once again need to update at least one section of his Facebook profile.

The FBI complaint against Harroun.