Law enforcement officials in the U.S. tell ABC 7 Chicago the target was a train traveling between New York and Canada.
In a rambling statement, suspect Chiheb Esseghaier seemed to say he did not recognize the court's jurisdiction.
"This criminal code is not a holy book," Esseghaier said at the hearing. "We cannot rely on the conclusions taken out from these judgments."
At the hearing Esseghaier rejected the allegations against him and declined to be represented by a court-appointed lawyer.
The judge urged him to take the advice of his lawyers.
He's due back in court on May 23rd.
The Associated Press contributed to this report