DEMOGRAPHER Paul Cheung is not a big fan of Facebook, Twitter or YouTube.

He likes to keep what is personal private, and is amazed at how youngsters willingly divulge the nitty-gritty details of their private lives or 'geotag' - assign geographic location data to - personal photos or videos on these social websites.

Yet as the director of the United Nations Statistics Division, one of the key charges for him is to promote the 'geocoding' of census data around the world.

Geocoding is the process of assigning geographic coordinates to street addresses and locations.

'Maybe I belong to a generation who views putting information on YouTube and Twitter more of a liability than fun,' said the 57-year-old Hong Kong-born Singaporean.

Privacy is such a concern of his that he would not even talk about his family - except to say that he has two children studying in the United States and they are 'around' 20 years old - when asked.

Going places with geotags