Facebook and other online networking sites have become an integral part of people's lives, but some wonder whether the sharing of photographs might be an invasion of privacy and, in some cases, even illegal. Such concerns have done little to stem the flood of new members to Facebook, however. According to figures provided by Google, the phrase 'Facebook login' was the third most searched keyword after 'Sarah Palin' and 'Beijing 2008', proving how widespread and popular the website has become. But Hong Kong's privacy watchdog advises people not to post others' personal data on the site. With so many cameras around, it is not uncommon to see less than flattering snaps appearing on the Net and in party photos. There are often other people in those pictures who may not want to be seen. If someone in the background of a photo can be identified, they can sue the one who posted it for breach of privacy. This means before you post a group picture, you need to be sure everyone in the picture is happy about it being there. Posting pictures of people on the internet without their permission may seem innocent, but it can be an offence in Hong Kong, according to the Office of the Privacy Commissioner for Personal Data. The statutory body was set up to oversee the enforcement of the Personal Data (Privacy) Ordinance. A spokeswoman for the office said anyone putting personal data, such as names or photographs, online without the consent of the owner violates the Personal Data (Privacy) Ordinance, which means they can be penalised. While it's not likely you will be tossed in prison for an innocent snap, you need to be aware of the legal pitfalls and take others' feelings into account. In July 2007, the City University of Hong Kong Quality Evaluation Centre (QEC) interviewed 500 young people between the age of 12 and 24 on their opinions on the sharing of personal data, photographs and videos on the Web. About 30 per cent of the students interviewed said they did not like friends posting pictures and video clips of them without their consent. They said it was a lack of respect and an invasion of privacy. Elvis Lam Tsz-lam, a Form Six student, said: 'One annoying thing about Facebook is when your photo is put on the Web, it can be viewed by people you don't know. These can be the friends of your friend and the list just goes on. When you put photos on Facebook you never know who's going to see them. I'm not comfortable with that.' Allen Wong, a university student who has been using Facebook for more than a year, said: 'Facebook is my platform for sharing photos. I love to put up photos of good restaurants I've visited. I also put up photos of my friends and me at gatherings and parties. Before I upload any photos I ask them for permission and I expect them to do the same. It's just basic manners to ask before using other people's photos.'