Toronto G20 protester Byron Sonne walked out of a downtown courthouse a free man Tuesday, tearing up his bail papers after he was cleared of possessing explosives and counselling mischief not committed.

The 39-year-old self-described computer security geek waved his hands and flashed the "victory" sign as he spoke to reporters under sunny skies and amid cheers from his supporters.

"I'm sorry, I'm just totally high on happiness right now," Sonne said, adding that his next plan was to celebrate his "utter vindication" with "a bit of a shindig" at a downtown bar.

Sonne, a hacker and hobby chemist, made headlines after acknowledging he was keen to expose gaps in the June 2010 G20 summit's billion-dollar policing scheme and provoke authorities.

Police raided his upscale Forest Hill home days before the summit was set to open, and found several containers of chemicals. The Crown had argued the cache of legal chemicals found in his basement — such as hexachloroethane, tetrahydrofuron and methyl hydrate — could have been bomb-making ingredients.

Sonne contended that the seized materials were for his rocketry hobby.

Police also seized potato guns from his cottage.

Sonne was charged with four counts of possessing explosives, and one of counselling mischief not committed in relation to his apparent urging of others to scale the security fence set up around the summit site.

Outside the courthouse on Tuesday, his lawyer Joe Di Luca reminded reporters that Justice Nancy Spies ruled there was nothing to support beyond a reasonable doubt arguments that Sonne meant to create explosives or cause any real damage at the violence-marred G20 protests.

"He's exonerated on that issue, and that's an important fundamental issue for Byron," Di Luca said.

Still, the judge noted that some of Sonne's actions could have been irresponsible.

Sonne spent 11 months in detention, though he has been out on bail for the past year.

His artist wife, Kristen Peterson, was also arrested, although charges against her were eventually dropped.

The couple has since split up and Sonne has been living with his parents, who regularly attended the proceedings, as have several supporters who considered him a political prisoner.

Web activity raised red flags

Speaking to reporters on Tuesday, Sonne said the crumbling of his marriage was the biggest emotional blow following the charges.

"Obviously the most biggest, most painful thing through this was just having completely my whole marriage fall apart and being abandoned that way," he said. "And it would be nice to be able to walk out of the courthouse and into her arms, but that' just not going to happen. But otherwise this is about as good as it gets. I can't believe how good this feels, just to be completely vindicated."

Byron Sonne talks to media outside court with his lawyer Joe Di Luca, left, after a judge said the Crown failed to prove the Toronto man was planning to combine chemicals to make bombs. (Aaron Vincent Elkaim/Canadian Press)

During the trial, court also heard that Sonne had made postings on internet forums about subverting G20 security measures, and police said they were suspicious of his online activity, such as his boasting to friends about purchasing certain chemicals that would have raised counter-terrorism red flags.

Court saw hundreds of photographs Sonne took of surveillance cameras, police and the security fence set up downtown —many posted online on photo-sharing sites — along with suggestions he made on how to scale the barrier.

Sonne argued they were just the harmless musings of a security geek, not a terrorist mastermind.

Near the end of the trial last month, a Toronto bomb unit was back at Sonne's former Forest Hill residence to remove more chemicals, which were later destroyed at the Leslie Street Spit.

Sonne's supporters say the police got carried away because of his political views about the G20. "They found these hobbies, and they destoryed his life over them," one supporter said outside the courthouse.

"I'm free," he said Tuesday. "I can actually talk to people on the phone; I can actually — not that I care about Twitter, that's mostly for morons anyway — but at the same time, I can be a moron again on the internet."

Sonne openly admitted he was trying to test the limits of the G20 security, but he said he's not likely to stop.

"It's more important than ever that we fight against the slippery slope of what's being done with our rights," he said.

The Crown previously dropped five other charges, including mischief, possession of a dangerous weapon and intimidating a justice system participant.