One of the highest-profile defendants charged with criminal offences stemming from the G20 summit in Toronto two years ago will learn his fate today.

Byron Sonne, who made headlines with his self-described attempt to expose gaps in the summit's billion-dollar policing scheme and to provoke authorities, faces four counts of possessing explosives and one charge of counselling mischief not committed.

Ontario Superior Court Justice Nancy Spies is to deliver her judgment starting at 10 a.m. ET in a downtown Toronto courtroom.

The judgment was delayed several weeks because, in another headline-grabbing incident after the main part of the trial was over, the police bomb squad descended on Sonne's former home last month to unearth what they said were "hazardous materials" buried in his backyard.

Circumstantial case

The Crown concedes that Sonne (whose surname rhymes with "honey") never possessed any actual explosives and that nothing he had is illegal on its own. Many of the substances seized amid the chemistry equipment in his home, including acetone, hydrogen peroxide and ammonium nitrate, are the main ingredients in common household products such as nail-polish remover, hair bleach and fertilizer.

But the Criminal Code says the crime of possessing an explosive includes having "anything intended to be used to make an explosive substance." Prosecutors maintain that the circumstantial evidence, particularly the sheer quantities of ingredients Sonne kept, shows he indeed had them for the purpose of synthesizing explosives, even if he had no concrete, detailed plans to ever do so.

Defence lawyers and Sonne's supporters say that totally misconstrues the intentions of the peaceable, highly intelligent IT professional, whose goal was simply to test how much the June 2010 G20 security apparatus would encroach on people's liberties.

Madison Kelly, a Toronto computer specialist and friend of the defendant, said there are perfectly innocent reasons Sonne kept a chemical cache: he was hobbyist in rocketry and chemistry, enjoyed gardening with his then wife and, like many hackers in the traditional sense of the word, had a passion for tinkering with things.

"There's nothing here that says he was going to do something wrong," Kelly said in an interview. "They jumped to the conclusion that everything he had had a nefarious purpose, partially because of his political views."

Potato cannon

Those "nefarious" things included a potato cannon at his parents' cottage, for which police initially charged Sonne, 39, with a weapons offence. The charge was later dropped.

Police also made a big fuss early on about a "waveguide" that Sonne had in his garage, claiming it was an electromagnetic weapon to disrupt telecommunications. It was really just a physics experiment to see whether he could redirect energy from a microwave oven. In the end, he wasn't even able to melt chocolate with it and had disassembled it.

In court documents, police also claimed that he had a detonator that turned out to be just a temperature sensor, and that he was trying to intimidate officers ahead of the G20 by taking pictures of them. Those charges were dropped, too.

Friend and fellow rocketry enthusiast Fryderyk Supinski said Sonne — whose resumé includes a certification in computer security and a private investigator's licence — was just keen to hold government to account for the nearly $1 billion spent on G20 summit security. That's why he shot video of the fence and security cameras erected around downtown Toronto and posted pictures of them, along with some photos of police constables, online.

"He was documenting some of the security apparatus, asking what kind of setup is there, what's the $1 billion that's being invested by us and giving a critical eye to it so that our government isn't wasting money. It's also to do with ensuring that some of the stuff that is deployed is taken down after the fact," Supinski said.

"The police are looking at this, and they're like, 'What is this guy doing? He's documenting our setups?' For them, there's no benefit in him doing that. It's likely going to make them look bad. So for Byron, he's doing other hobbies which are being essentially leveraged against him to trump up what he's doing downtown."

Kelly said prosecuting Sonne has cast a chill over Toronto's hacker community, many of whom "have the same stuff."

"What if we say something against the sitting government, or against the police? Because he was a geek, because he had nonstandard interests, and because he had pissed in the police’s cereal, they used these things against him," she said.

Lost wife, house

Sonne's legal saga has cost him dearly. His wife, who was arrested on accusations she conspired with him before those charges were dropped, divorced him. He no longer lives at their home in Toronto's tony Forest Hill neighbourhood. His legal bills are in the tens of thousands of dollars, and he spent 11 months in pre-trial incarceration before getting bail.

If he's convicted, his charges carry a maximum sentence of 25 years, though the penalty would almost certainly be much lower.

Sonne's defence lawyers, Joseph Di Luca and Peter Copeland, said neither they nor their client would do interviews ahead of the judgment. Prosecutor Liz Nadeau likewise declined to answer questions.

"He’s anxious to see this over with. It’s a tremendously stressful experience," Kelly said. Asked whether Sonne will continue to "tickle the dragon," as he once characterized his agitating, if he's acquitted, Kelly replied: "I would say from my experience: Yes he will, because he knows what he did is right."