A team at the University of Cambridge says that its new approach that not only looks at friends of friends, but also the places people visit -- with weightings given to different places such as airports and gymnasiums.

'Essentially this is a way in which we can predict how people will make new friends. We know that we are likely to become friends with 'friends of friends' but what we find is there are specific places which foster the creation of new friendships and that they have specific characteristics,' team leader Salvatore Scellato was quoted by the British media.

The research looked at the problem from the perspective of a long-standing sociological theory that people who go to the same places may be similarly minded. That would make them individuals likely to form a connection with one another.     

To test their theory, the researchers used data from four months at a relatively small but fast-growing website, called Gowalla. to see how social connections grew in that time.     

'We discovered that about 30 per cent of all new social links appear among users that check-in to the same places. Thus, these 'place friends' represent disconnected users becoming direct connections.

'By combining place friends with friends-of-friends, we can make the prediction space about 15 times smaller and yet, cover 66 per cent of new social ties. It turns out that the properties of the places we interact can determine how likely we are to develop social ties.

'Offices, gyms and schools are more likely to aid development rather than other places such as football stadiums or airports. In those places, it's highly unlikely people will develop a social connection,' Scellato said.

Meanwhile, Facebook has closed a social networking page that encouraged Irish republicans to post pictures and personal details of Northern Ireland police officers.

Facebook took the action after Northern Ireland police and politicians complained that the page, called Crown Forces Watch, was an intelligence-gathering tool for Irish Republican Army dissidents.

IRA splinter groups regularly plot attacks on police officers, who are most vulnerable when off duty. In April, a policeman was killed when a bomb exploded outside his home under his car.

For decades, Northern Ireland police shielded their names and home addresses from public disclosure because of the threat of IRA attack. Such security has eased since the IRA's 2005 decisions to disarm and renounce violence.