data shadow
n. The trackable data that a person creates by using technologies such as credit cards, cell phones, and the Internet.
It's not only spam that worries Garfinkel. It's the power that businesses wield with personal information. Take the case of a Los Angeles man who injured his leg in a supermarket; when he sued, the market used records of his alcohol purchases to malign his character. Our 'data shadows' — a term coined by Columbia professor Alan Westin — 'force us to live up to a new standard of accountability,' Garfinkel writes.
—Alex Lash, “Private Eyes,” The Industry Standard, February 21, 2000
1992 (earliest)
Decisions taken solely on the basis of one's 'data profile' or 'data shadow' have raised great concern in Europe where a comprehensive privacy policy is now under consideration.
—Marc Rotenberg, “Electronic Monitoring of Employees,” Law & Policy Reporter, March 01, 1992
As the first citation says, the coiner of data shadow was Alan Westin, who first used the term in his 1967 book, Privacy and Freedom. However, it took over 25 years before we started to see the term used in the mainstream press.