The State of California has joined Europe in observing the second annual Data Privacy Day.

California governor Arnold Schwarzenegger issued a declaration which officially recognises the observance of the day.

More than 27 countries in Europe, along with Canada and several US states, are participating in the event, which is designed to boost consumer awareness of protecting personal data online.

California was the first US state to establish an official Office of Privacy Protection, which aims to teach users how to protect their personal information.

"More and more we use our computers for sensitive transactions such as banking and filing income taxes while viruses and spyware on the internet are multiplying," said Rosario Marin, Secretary of the State and Consumer Services Agency.

"That's why it's so important to remind Californians that we have resources available to teach them how to protect themselves on this California Data Privacy Day."

California is also home to the companies that operate some of the largest data repositories on the web, among them Google and Yahoo, both of which are running privacy campaigns of their own.

"The lack of understanding about online data protection is a global issue," wrote Google privacy counsels Peter Fleischer and Jane Horvath in a blog post.

"As increasing amounts of data get uploaded to the internet every day, it becomes more and more important for people to understand the benefits and risks of online communications, and to learn how to use available tools to control and manage the information they share online."