Google boss Eric Schmidt warns that one day young people may change their names in order to overcome what they had done in social networking world.
Mr Schmidt told the Wall Street Journal he feared they did not understand the consequences of having so much personal information about them online.
On his prediction that people may change their names, Mr Schmidt said: "I don't believe society understands what happens when everything is available, knowable and recorded by everyone all the time... I mean we really have to think about these things as a society."
However, Mr Schmidt said that Google would likely store more personal information about its users in the future.
At the moment, he said, "we know roughly who you are, roughly what you care about, roughly who your friends are."
But, according to some experts, his concerns about the future are "overstated".
"The idea that everything is stored online is not true," social media consultant Suw Charman-Anderson told BBC News.
"It will be quite some time before that can become true because of the enormity of the internet."
Archives such as Google Cache, which store older versions of websites, are selective, she added.
"Google Cache is a snapshot taken periodically of some of the internet. It's very hit and miss at the moment."