However, before the hearing could begin she glued her hand to the window of the dock.
“I have glued my hand,” she told the court.
Liam Norton, 37, who had entered the court to support her, then walked up to the witness box while filming with his phone.
He was rushed and tackled by court staff as he approached the box.
Warner then pulled her mobile phone out in the dock and began to film herself.
Ana Heyatawin, 59, also pulled her phone out and began to film the proceedings.
She then glued her hand to a bench inside the court.
Police officers then arrived, clearing the press from the court.
The Metropolitan Police later said three people had been arrested.
A spokesperson for the force said: “A 37-year-old man was arrested for attempted criminal damage and assault on an emergency worker, a 63-year-old woman and a 59-year-old woman were arrested for criminal damage after they glued themselves to furniture in the court room.
“A police de-bonding team unstuck the three people.
“All three have been taken into custody at an east-London police station.”