On the ground at BarCamp Sydney

Aside from e-business, one of the most heated debate topics was privacy. Laurel Papworth, a social networks strategist and lecturer at the University of Sydney, said that people placed a lot of trust in companies to keep their information private.

"What if Google suddenly published all of your searches? Or your Facebook pictures became publicly available? Now that you can run a reverse IP search on your Wikipedia entries, everyone knows if you're the person who edited the herpes page with a lot of detailed information. Some people would find that highly embarrassing."

Papworth recently spent a week in Saudi Arabia teaching women how to write blogs. She said that the women had cultural concerns about privacy on the internet. "Many of these women were worried that photographs of them would appear on sites like Flickr. This would be devastating to them. They were highly aware of the 'invisible audience' provided by the internet."

Papworth's concerns were echoed by Liam Hodge, a 16-year-old high school student who talked about the Anonymous movement.

The Anonymous movement was formed in 2005 by participants in various online forums. While its basic aim is to promote free internet speech, it is an emergent internet culture, with no internal structure or leadership. The movement has become known for its vocal opposition to Scientology; in 2007, an anonymous person promised to "remove Scientology from the internet" on behalf of the movement.

"At a rough count, there are 20,000-30,000 people involved in Anonymous," said Hodge. "It became extremely important to protect the anonymity of the people involved, because of the threat of government and private retaliation. The internet should be free, and people should be able to say what they like, without fear of being shut down."

An audience member agreed. "There are a lot of draconian laws about what can and can't be discussed on the internet. Euthanasia is a classic example. But people on the internet will always seek a way to circumvent these laws."

Hodge said that attempts to shut down the Anonymous movement would ultimately be unsuccessful. "The internet is resilient. The harder you push it, the more it will rally around an issue."