From the surveillance entertainment of Big Brother to CCTV and celebrity magazines, the boundaries of what is regarded as appropriate to put in the public domain are shifting dramatically. But nothing is challenging our notion of privacy more than social networking, with 26 million of us using Facebook to share the minutiae of our lives every month in the UK alone.
Facebook has proved irresistible to many because we are lured into joining by friends and family. Browsing, reading, comparing and nosing is instinctive, impulsive and reflects our tendencies offline, our "social graph", as Facebook founder Mark Zuckerberg likes to call it. Having executed the social networking business idea better than its rivals – MySpace, Bebo, Friendster and Hi5 have been left for dust – Facebook has seen astonishing growth, from a Harvard dorm project in 2003 to a global phenomenon that had 500 million monthly users by July this year. That's already one in 13 people on Earth, and Zuckerberg recently predicted it was "almost a guarantee" that his site would reach 1 billion users, with growth in relatively untapped markets such as Russia, Japan and Korea "doubling every six months".
On Thursday, Facebook unveiled its latest gambit in the battle to remain top of the social networking heap with a move into geolocation services, which harness the GPS functionality of increasingly powerful mobile smartphones. Facebook Places will launch first in the US and later in the UK, allowing users, if they choose, to share their location with friends on the site by checking into public venues. Sensitive to intense public scrutiny of its privacy controls, Facebook was careful to make the service opt-in but every geolocation service – including Google's Latitude, Gowalla and Foursquare – has prompted renewed debate about the protection of personal details online.
"This is a seminal moment where we're seeing new thinking and new practice starting to emerge around the issue of privacy," says Stephen Balkam, chief executive of the Family Online Safety Institute and member of Facebook's safety advisory board. "The battle lines are being drawn between generations. Facebook is headed by someone who hasn't hit 30 yet, but has very different perceptions and assumptions about what is private and what is not. We need to recognise that with social networking, geolocation and digital technology, the privacy bar is being reset."
Facebook has come under significant pressure to make its site safer for users. Incidents of serious crimes facilitated by the internet such as the murder of British teenager Ashleigh Hall by Peter Chapman earlier this year, are tragic but rare. More common is the embarrassment from a compromising tagged photo of a drunken night out.
The rapid pace of development by technology companies often throws up new cultural and ethical challenges. Google's Street View has frequently been challenged by privacy campaigners who question whether the logistical and commercial benefits of making every property in every street visible on the web are worth the sacrifice of the individual's right to privacy. Facebook users first raised their pitchforks in 2006 when the site introduced a news feed for each user, summarising their friends' activity. More recently it came under pressure to simplify its privacy controls with some high-profile commentators and groups – organised on Facebook pages, naturally – encouraging others to remove their profiles. It responded in May with simplified privacy settings.
Richard, now Lord, Allan is a former Liberal Democrat MP and Facebook's European policy director. "The internet is here to stay as a ubiquitous way for every individual citizen to capture and share information. The...