A man who made online threats against the creators of South Park for perceived insults against the prophet Muhammad has been sentenced to nearly 12 years in prison.

Jesse Curtis Morton, 33, a convert to Islam who founded the now-defunct Revolution Muslim website, was sentenced in Alexandria, Va., on Friday.

Another co-founder Zachary Chesser earlier received a 25-year sentence, but he had also tried to travel to Somalia to join the al-Shabab terrorist group.

The thinly veiled threats against the creators of South Park appeared on the site after the television show depicted Muhammad in a bear costume.

U.S. District Judge Liam O'Grady told Morton he went beyond his First Amendment rights with the site.

"There has to be religious tolerance in the world. There has to be freedom of speech," Judge O’Grady said, berating the defendant for not using his intelligence to promote tolerance.

Morton apologized for his conduct, saying: "I justified atrocities by Muslims simply because they were carried out by the weak against the powerful."

Morton agreed with the judge that Revolution Muslim crossed the line when it carried the al-Qaida magazine Inspire which frequently called for violent jihad.

Prosecutor Gordon Kromberg had argued that a stiff sentence was necessary because Morton's site appealed to others involved in criminal acts, including Antonio Benjamin Martinez, who plotted to bomb a military recruiting station; and Jose Pimental, who plotted to assassinate members of the U.S. military returning from Afghanistan and Iraq.

Defence attorney James Hundley had sought a prison term of less than five years, arguing that Morton sought to engage in “religious dialogue.”

Morton was prosecuted under a recent law that makes it a federal crime to use the internet to place another person in fear of death or serious injury

With files from The Associated Press