SF Gate
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/08/27/BA0419E2FH.DTL
“It will be a very difficult case to prove,” said Chris Hoofnagle, a lecturer at the UC Berkeley Law School who focuses on information privacy.
There are two major problems with the approach, he said. First, while there’s a legal obligation of trust between doctors and patients or lawyers and clients, no such inherent understanding between a blogger and a free online service has been recognized by the courts.
Second, even if Port does successfully argue that such a relationship existed, Google can claim that its duty was limited – in the same way that a lawyer can break his confidentiality obligation to prevent a crime. The company could maintain that it complied by not revealing Port’s identity up until the point it was ordered to do so by the court.