Only the judge and lawyers could see "John" behind a large screen in a Toronto courtroom. The Canadian spy entered through a separate entrance each day last week and a "Do Not Enter. Sealed by Judge's Order" sign hung on the door as he took his place on the hidden witness stand. While his identity may have been shielded, the agent's testimony in the extradition case of Abdullah Khadr gave an unprecedented glimpse into the covert world of international terrorism cases. John told the court that the Americans wanted to render Khadr to a U.S.-run foreign prison – perhaps Guantanamo Bay or one of the undisclosed "ghost sites" – but that the Canadians and Pakistanis refused to consent to his transfer. He testified about the $500,000 bounty the CIA paid the ISI, Pakistan's intelligence agency, and gave detailed answers about the delicate dance that went on between Ottawa, Islamabad and Washington. It seems everyone wanted information from Khadr but no one had the evidence to charge him – until Khadr confessed – which is the crux of the case. Was his abusive treatment (which the prosecution conceded took place after his arrest in Pakistan) enough to render anything he said about purchasing weapons for Al Qaeda inadmissible (even when he repeated these claims in Canada?)If Ontario Superior Court Judge Christopher Speyer throws out Khadr's statements, then the case crumbles, and Canada would be unable to extradite the 28-year-old Canadian to the U.S. for trial. The case continues this week.

But beyond answering questions that have lingered for years about Khadr's case, John's testimony was a remarkable example of how the Canadian Security Intelligence Service is being forced into public.

"There really has been a paradigm shift in what is being disclosed and what's not," noted Toronto lawyer Lorne Waldman, who represented Maher Arar during a multi-million dollar federal inquiry.

Much of the Arar inquiry examining Canada's role in the Ottawa engineer's rendition and detention to Syria was conducted behind closed doors. The censorship prompted commission counsel Paul Cavalluzzo to reveal an 89-page government document one day during the 2004 hearing, showing journalists how every word had been blacked out.

Waldman says he believes the change that opens CSIS to public scrutiny is due to the federal courts becoming "a bit less deferential and more assertive."

But how far will the courts push, and what does this mean for the future of how security investigations are conducted?

Last Wednesday, a Federal court judge ordered CSIS to hand over the file in the case of Mohamed Harkat, an Ottawa terrorism suspect the government is trying to deport with a national security certificate. Justice Simon Noël told CSIS it is time to realize agents will be called as witnesses in these cases.

"This is the new reality," Noël wrote.

The debate is not limited to Canada as the U.K., Australia and U.S., among other countries, have had similar court challenges in figuring out how security can be maintained while civil rights respected.

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