Your Data lives forever on the internet

Viktor Mayer-Schönberger has been thinking and talking about the inability of the Net to forget for quite a while now (ArsTechnica, 2007, (german) re:publica'08: Keynote: Nützliches Vergessen).
Now his new book came out "Delete: The Virtue of Forgetting in the Digital Age" (Princeton Press)

The balance between privacy and a social online life is not easy to define and implement in practice. Social networking and social media (a.k.a. sharing culture) has become second nature to many of us, while other avoid or even outright reject to "make their private life public".

Allow me to share two aspects, which seem essential to describe and understand (my) social media life:

Networked publics are to be differentiated from the classical terms 'audience' and 'public'. The information I share on internet is interesting and relevant only to a limited group of people, most of which I know personally. One shares information in different groups (publics). And rather than "presenting" to an audience, it is more like a conversation at a (public) party.

The other concept is self-fashioning (wikipedia). A term that was introduced "to describe the process of constructing one's identity and public persona according to a set of socially acceptable standards." Originally applied to how people at the court of Renaissance kings used to design and live their roles like in a theatre play. It remindes me of "The Presentation of Self in Everyday Life" (Erving Goffman).
Putting information online is a concious act upon which most of us reflect regularly. The image, the mirror of our lifes we share online is a "positive" is a persona perspective.