Oh, and on the topic of personal information that can be potentially harmful. Not to be tin hat here... but consider
genetic information. I feel this has the potential for great harm, and is for the most part currently being overlooked.
Private genetic testing for ancestry & health are popular, and heavily marketed ("It makes a great Christmas gift!"). That information too is supposedly private; but recent law enforcement cases have shown that genetic information can be accessed by subpoena (or sometimes without one) to search for matches to crime scene DNA. Current precedent suggests that practice will become much more widespread.
But more importantly IMO, consider the value genetic testing could have to an insurance company - particularly health insurance. If those companies could know your genetic predispositions to serious illness, they could increase your premium, or deny you coverage, probably without even telling you why.
And they might reasonably assume your descendants had the same issues, and treat your whole family the same way. There are laws that specifically prohibit such use... but if those decisions were made surreptitiously, who would know? That genie could negatively impact generations, and should never be let out of the bottle... which is the reason that for our children's sake, neither DW nor I will willingly submit to such testing.
See
here for the current Federal Genetic Privacy law.
Links to state DNA laws can be found
here.
A really good discussion of the issues surrounding personal genetic data is here:
The US Urgently Needs New Genetic Privacy Laws
.
. My hat's off too you sir 
