New Comm Tech

For the essay, my chosen question will be:

Why is privacy such a contentious issue for internet users?  Discuss with reference to at least ONE social network service (or other web2.0 service).

Already, I have located three interesting sources to aid me in my research:
1. http://www.wired.com/politics/security/commentary/securitymatters/2006/05/70886
2. http://conferences.sigcomm.org/sigcomm/2009/workshops/wosn/papers/p7.pdf
3. http://news.bbc.co.uk/2/hi/technology/6199372.stm