A new computer program increases the risk of private account hacks on Facebook and Twitter.

Firesheep, a program that is available for download on the Internet, gives hackers access to the user accounts of people who use unsecured wireless networks.

According to a report from Australia's Sunday Mail, Firesheep allowed testers to gain access to 15 Facebook accounts and an email account from Hotmail in just under 20 minutes.

Carina Schmeissi, an Australian backpacker, was appalled after being approached by the Sunday Mail. "Oh my God... It's awful. I am shocked. That is really scary," she said.

Anna Westrin, a student whose account was hacked when the Sunday Mail tested the program at the State Library of Queensland, was equally stunned. "I think it's really scary that it's so easy, especially if you can just press one button... I wouldn't believe it if I hadn't seen it for myself. I'll definitely be a lot more cautious from now on.''

The program, which comes as a free add-on to the Firefox Web browser, allows users to gain access to 26 popular Web sites. The list of sites Firesheep can gain access to include Yahoo, Facebook, Twitter, Hotmail and Amazon.com.

Since three days after its release date, more than 200,000 people downloaded the program.