A teenager from the suburbs of the US city of Chicago has been arraigned on terrorism charges in connection with an FBI sting operation that has raised new questions about whether US investigators are engaging in entrapment. Abdella Ahmad Tounisi, 18, made a brief court appearance Tuesday in federal court in Chicago. The American-born man from the Chicago suburb of Aurora is accused of seeking to join al-Qaeda-affiliated Jabhat al-Nusra, which is fighting Syria’s government in a civil war. He tried to join the group through a website, constructed by the FBI, which urged readers to “join your lion brothers… fighting under the true banner of Islam”. Critics have said the use of such sites raises questions about whether authorities are overreaching, wooing impressionable youth to contemplate crimes that otherwise wouldn’t cross their minds. “These sites can end up creating crimes,” said Phil Turner, a former federal prosecutor turned defence attorney in Chicago. “Real terrorists don’t need to go to a website for contacts. They have real contacts.”