A federal judge in Boston sentenced a Massachusetts man to 17 ½ years in prison Thursday for conspiring to aid al-Qaida terrorists.

Tarek Mehanna was convicted in December on charges related to a plot to kill U.S. soldiers overseas. Mehanna and two co-conspirators traveled to Yemen in 2004 to seek training in a terrorist camp with the goal of plotting jihad against American troops stationed in Iraq. After failing to find a camp, Mehanna and others returned to the United States to plot attacks within the United States including randomly shooting people in a shopping mall. Mehanna also launched his own online al-Qaida "media wing" to translate and distribute publications by the terrorist group.

Prosecutors sought a 25-year sentence in a memorandum filed Tuesday. A lengthy sentence would act as a deterrent to jihadi wannabes seeking to imitate Mehanna's actions, they argued, including traveling overseas to obtain terrorist training as well as using the Internet to publicize al-Qaida's violent message.

Mehanna "continues to have no respect for American law and would reoffend if given a chance" they argued "A lengthy prison sentence and period of supervised release is needed to ensure that he does not get that opportunity."

Mehanna's attorneys say he visited Yemen for religious purposes and his online jihadi activities were protected by the First Amendment.

"There was no evidence that Mehanna's actions actually threatened United States security interests. There was no evidence that Mehanna provided any tangible material support such as funds or weapons to terrorist activity or to Al Qaida," Mehanna's lawyers wrote in their sentencing memorandum.

Mehanna had denied plotting the murder of Americans and justified his actions as "self-defense."

"I never, ever plotted to kill Americans at shopping malls or anywhere else," Mehanna is reported to have said. "Muslims should defend themselves against foreign invaders. This is not terrorism or extremism. It's self-defense."

When Assistant U.S. Attorney Aloke Chakravarty told U.S. District Court Judge George A. O'Toole, Jr. that Mehanna's assertion was "categorically false," Mehanna reacted screaming, "You're a liar, you're a liar!"

Mehanna also alleged the government prosecuted him because he refused to become an informant.