Two supporters of Army Pfc. Bradley Manning were barred Monday from the accused WikiLeaker's preliminary military hearing at Fort Meade.
The American Civil Liberties Union, meanwhile, said it would appear in federal court Tuesday to challenge the government's "suspicionless search and seizure" of a computer owned by another Manning supporter.
Former Lt. Dan Choi, who attended the Article 32 hearing on Saturday and Sunday, tweeted that he was "pressing charges" after he was barred from entering Monday.
Choi, a gay West Point graduate who was prominent in the campaign against "Don't Ask, Don't Tell," said he was handcuffed and pinned to the ground by the security detail outside the courtroom.
"They ripped off my rank," he tweeted, and "they were very angry that I wore my uniform."
The Military District of Washington said Choi "created a disturbance" outside the courtroom. In a statement, the district said Choi violated the terms of the hearing by "calling out ranks and names of individuals in uniform supporting the procedures."
When he refused to stop, the district said, "Mr. Choi was combative, which required the security personnel to restrain him for his own safety, and the safety of the escorts."
Choi tweeted: "The Fort Meade PAO lied (big surprise)."
The district said Choi would not be allowed to return to Fort Meade for the rest of the day on Monday.
Daniel Ellsberg, the former military analyst who leaked the Vietnam War records known as the Pentagon Papers, was escorted from the courtroom after he attempted to introduce himself to Manning during a recess.
The ACLU, meanwhile, said Homeland Security agents seized the laptop computer, camera and USB drive of Manning supporter David House in 2010 as he returned to the United States after a vacation.
The ACLU said the government had targeted House "solely on the basis of his lawful association with the Bradley Manning Support Network."
"House's detention and interrogation and the seizure of his electronic papers and personal effects had no apparent connection with the protection of U.S. borders or the enforcement of customs laws," the ACLU said.