James Tanner is a genealogist, a blogger, and has been a trial attorney for the past 39 years. When it comes to privacy issues, he knows what he is talking (and writing) about. He has published an article in his blog about privacy issues as they relate to genealogy. I would suggest every genealogist should read his article at http://goo.gl/2Lq3G9.
Tanner points out:
"If I even mention putting your genealogy online in a family tree, somebody in the class has an almost violent negative reaction."
"I can say this with certainty: the usual perception of the extent of "privacy" is far greater and more encompassing than the reality. Privacy is one of those words everyone uses and no one really knows what it means."
"...the incidence of true, hard-core identity theft is extremely rare."
You can find James Tanner's excellent Commentary on Privacy and Family Trees at http://goo.gl/2Lq3G9.