Credit card companies know what you've bought. Phone companies know whom you've called. Electronic toll services know where you've gone. Internet search companies know what you've sought.
It might be reassuring, then, that companies have largely pledged to safeguard these repositories of data about you.
However, a recent federal court ruling ordering the disclosure of YouTube viewership records underscores the reality that even the most benevolent company can only do so much to guard your digital life: All their protections can vanish with one stroke of a judge's pen.
"Companies have a tremendous amount of very sensitive data on their customers, and while a company itself may treat that responsibly ... if the court orders it be turned over, there's not a lot that the company that holds the data can do," said Jennifer Urban, a law professor at the University of Southern California.
