The Federation of Canadian Naturists says it's ignorance that led to the cancellation of a private naked swim event in Calgary, but they understand why the city did it.

"I think it's actually a wise decision, unfortunately," Ron Schout told The Homestretch from Toronto on Thursday.

"I've seen radicals in motion before and I would have no idea what could possibly be pulled off, no matter what kind of police protection or security."

The city announced Thursday the event planned for Sunday was being cancelled over security issues.

An online petition launched by April Parker against the event drew more than 20,000 signatures, many from outside of Calgary.

Schout says he's stunned by the ignorance of some people who have never researched the issue.

"As far as the outcry from the petition, that tells me that we've still got at least [several thousand] people to educate about how the naturist lifestyle is, how it actually affects the whole family and the benefits of the lifestyle."

'Why does it always have to be sexualized?'

He's concerned that a swim with parents and their children has been sexualized by outsiders.

"What is wrong with our body? Why does it always have to be sexualized? These are not sexualized swims at all. This is just swimming, having fun — and it's family fun," he said.

Schout said it's likely social media and the petition that put the issue on the radar of people who wouldn't have been aware of it otherwise.

"Everybody registers. That registration is checked by photo ID. That's in most of our clubs. The parents come with their children and are with the children in the swim."

With files from The Homestretch