Increasing amounts of personal information are collected by
organisations and stored in massive databases. That information is
sometimes used or released after being stripped of elements that
could identify individuals in a process called 'anonymisation'.
University of Colorado Law School Associate Professor Paul Ohm,
though, has said that the techniques used no longer work and that
it is now possible to identify people from the release of
supposedly anonymised records.
"With the supposed power of anonymisation you can share the data
with anyone you want, you can store the data for as long as you
like," Ohm told podcast OUT-LAW Radio. "And traditionally it has
been a conversation stopper. Once you assert anonymisation everyone
nods their heads and says 'that's fine, privacy is protected here,
let's focus on something else'."
But even though you are deleting many of the identifying fields
of information, everything you leave behind retains identifying
power," he said.
Ohm said that research has shown that a combination of
increasingly powerful computers and the prevalence of large
databases has made it possible to "re-identify" people whose
records have been anonymised.
One researcher in Massachusetts about 15 years ago discovered
that 87% of Americans are uniquely identified by three pieces of
information: their date of birth, their sex and their zip [post]
code," he said. "Now the problem was that until she announced her
findings, zip code, birth date and sex were three pieces of
information that we presumed were privacy-protecting, were
anonymised. So they appeared in all sorts of databases."
Ohm told OUT-LAW Radio that the problem was huge because such
trust had been placed in anonymisation that it was enshrined in
legislation. "Virtually every privacy law allows you to escape the
strictures and requirements of the privacy law completely once
you've anonymised your data," he said. "Every policy maker who has
ever encountered a privacy law, and that's in every country on
earth, will need to re-examine the core assumptions they made when
they wrote that law."
Ohm said that the problem was hard to solve because the very
pieces of information that identify a person are the pieces which
are useful to researchers.
He proposed, though, that in some fields of research, such as
health, it would be possible to open up much more data than is
currently permitted as long as you controlled access to it.
"We can't trust technology any more but at the same time we
don't want to keep this information from researchers. So my
solution is that we shift our trust from the technology to the
people," he said. "We write down the rules of trust among health
researchers … [we say] you can get my data but only on a need to
know basis."
Hear Paul Ohm on OUT-LAW Radio
Please download the flash player to view this document
Browser does not support script.
Disclaimer: We hope you find OUT-LAW’s content useful. It’s prepared by the lawyers at Pinsent Masons. Please remember, though, that it’s intended as general information only. It’s not legal advice. If that’s what you’re seeking, please
contact us. See also: our
full disclaimer 