TORONTO - A man denied bail in a case related to G20 security is becoming the subject of an international campaign to have him freed.

Byron Sonne was arrested on June 22, just days before world leaders descended on Toronto for the G20 summit.

He faces charges of possession of explosives, weapons dangerous, intimidation of a justice system participant and mischief.

Tuesday's news that Sonne — an independent Internet security expert — was denied bail seems to have strengthened the resolve of the "Free Byron" movement.

"Now that we're looking at a few years of pretrial custody, this is something that's taking off quite rapidly," said James Arlen, a security consultant in Toronto and a longtime friend of Sonne's.

Arlen is in the process of revising five talks he'll be giving at an upcoming hackers' conference to include a plea for help for supporters of Sonne who want to see him released.

DEFCON is a premier hackers' event held in Las Vegas and attended by 5,000 to 7,000 people. Sonne had attended in the past.

"There are a few of us who are in positions where we get to stand up in front of crowds of people and talk and we're going to be talking about this," Arlen said.

"You're going to have a hard time finding a Byron supporter who isn't wearing a Free Byron T-shirt... and Free Byron stickers are going to be flowing like water."

"Everybody is going to be talking about this."

The details of the evidence presented in court are covered by a publication ban.

But friends and former co-workers have said they think Sonne's case comes down to a misunderstanding, and they called Tuesday's decision to deny bail an overreaction.

Mike Murray worked with Sonne for several years. He described the work they did as hacking into organizations to find their security flaws in order to help the organizations build stronger security systems.

Murray said he worries the skill set specific to hackers makes them vulnerable to prosecution.

"It's typical in the security industry where we have a lot of skills that could be used nefariously," Murray said on the phone from Atlanta.

"I think it's important for people in our industry to rally around this because it is easy to misconstrue what we do."

"It could be any of us," Murray said. "Byron could be any of us."

He said he'll be speaking up at DEFCON as well.

This is not the first time the hacker community has rallied around someone they feel has been wrongly incarcerated. Both Murray and Arlen brought up the case of Kevin Mitnick, a hacker they say served several years of jail time in the United States.

Technology expert Jesse Hirsh, another of Sonne's supporters, recalled hearing him speak at a meeting of surveillance buffs in Toronto in May.

Hirsh said Sonne detailed his plan to listen in on police communications during the G20 summit.

Sonne will become a "social media hero" when his case goes to trial and the public hears details of the evidence against him, Hirsh predicted.

"He will be a cause celebre," he said.

"Regular Canadians will be able to support this individual and this case ... because of the way he's being treated and the way that he's being prosecuted, which is ludicrous."

While the Crown described Tuesday's decision as "thorough" and "considered," Sonne's defence lawyer said she was disappointed.

"We will consider the options in terms of a bail review and start preparing for his trial," Breese Davies said.