Christian Stöcker writes:
At the invitation of the German government, an IT professor has introduced software that allows people to set an expiration date for photos they post on Facebook or other sites. What it can’t do, however, is prevent others from copying or stealing a person’s personal data and posting it wherever they want on the Internet.
The greater the urge to delete Internet data, the harder it seems to be to actually get rid of it. There is even a word for this effect and it comes from an incident that happened to Barbara Streisand.
Read more on Der Spiegel.