Facebook reached a major milestone this week with five hundred million users signed up the social networking site.

The internet site was started six years ago by Mark Zuckerberg with only a few hundred users.

But in the last 15 months, the company has exploded, adding around eight new users every second.

According to Facebook each of its users have around 130 'friends', and will share 70 different bits of their life with them each month, from pictures, passions, home movies and more.

This year the US social networking website announced that it was simplifying its privacy controls and applying them retroactively, so users can protect the status updates and photos they have posted in the past.

The announcement came amid growing concerns about privacy on the website - most recently complaints that the site forced Facebook users to share personal details with the rest of the online world or have them removed from Facebook profiles altogether.