European legislation covering the protection of private data is being dragged into the digital age in a potential threat for social networking sites like Facebook where users display foibles, often without a thought for consequences.
European Commissioner Viviane Reding cited the arrival of privacy issues raised by such social networking sites when she announced last week a flagship drive to rewrite European law for the Internet generation, turning the old 1995 text into something fit for purpose.
Data protection for private citizens is a sensitive issue in Brussels, which has been in conflict with the United States for years seeking greater controls on personal details gathered under anti-terror drives there.
The European regulators have also successfully pushed web and computing giants Google, Yahoo! and Microsoft to reduce the length of time they hold details that can be classed as personal, such as browser logs.
One of Microsoft's directors, Brad Smith, came to Brussels last week to call for "an advanced framework of privacy and security that is more closely aligned with the ways in which not only computing, but also the interaction between people, is evolving."
All the more necessary as the computer world -- and already public authorities in the US at least -- switches increasingly towards 'cloud' computing, which essentially means the storage of data in shared servers over the Internet.
Clear rules are needed to avert the sort of polemic that erupted around Google's 'Street View' application -- where entire cities are photographed for 'walk-through' online appreciation -- or around each change to confidentiality rules implemented by Facebook.
Canada this week opened a fresh probe into the leading social networking site, following its December decision to no longer allow members -- who number more than 200 million worldwide -- to hide certain details including pictures and personal profile, including lists of 'friends' or group memberships.
Facebook founder Mark Zuckerberg defended the move this month saying "social norms" had changed when it came to what individuals were willing or eager to share.
"In the last five or six years, blogging has taken off in a huge way and all these different services that have people sharing all this information," he said.
"People have really gotten comfortable not only sharing more information and different kinds, but more openly and with more people."
But the result is that Internet searches can bring up very personal details, with studies repeatedly showing how recruiters use these services to 'vet' potential candidates.
A recent addition, by researchers Cross-Tab, shows that 41 percent of recruiters said they had already refused candidates because of details about their lifestyles picked up through this medium. The figure hit 70 percent in the US.
Comments posted online and "inappropriate" pictures or videos can all trigger worries over lifestyle.
Recruiters "are for the most part comfortable searching for information that would be unethical or even illegal to ask a candidate to provide," the authors underlined.
Explore further: Study: Social media users shy away from opinions