From Why Privacy Matters
Richard Warner
The JulesVerne-O-Scope, Privacy, and the Internet
Imagine Brian invents a device—the JulesVerne-O-Scope—which
allows him to view a video-like display of any part of anyone’s past. When,
in the spirit of scientific experiment, Brian asks his friend, Brianna, to
consent to his viewing her past, she declines. She objects to losing control
over what Brian knows about her. She objects, for example, to his learning
what she is really willing to pay for the house she is offering to buy from
him; and, she objects to his learning facts she would reveal only to more
intimate friends—such as her feelings about her marriage. When she
withholds consent, Brian promises not to use the device, but she does not
trust him, and, over time, she begins to suspect he is viewing her past. She
begins to wonder constantly whether and to what extent what Brian says and
does in her regard is premised on knowledge he has obtained using the
JulesVerne-O-Scope. She fears Brian’s new found power and resents his
transgression of her boundaries of intimacy. The distrust, fear, and
resentment destroy the friendship, and Brianna eventually refuses even to be
in the same room with Brian.
Compare their pre-Jules-Verne-O-Scope friendship. Both were limited
in what they knew about each other, and, to a considerable extent, both
knew those limits: they knew what they did and did not know about each
other. Both knew that Brian did not know how much Brianna was willing to
pay for the house, and that he did not know her unexpressed feelings about
her marriage. Against this background of shared knowledge of knowledge
limits, Brianna was confident that Brian did not have unwanted power over
her in the house deal, and that Brian’s knowledge did not exceed Brianna’s
degree of intimacy. Brianna interpreted Brian’s words and actions against
this background, and, exceptional circumstances aside, did not worry that he
knew personal facts she desired he did not know.
In general, we conduct our relations with others against a background
of shared knowledge of the limits of our knowledge of each other. A device
like the JulesVerne-O-Scope would, if widely used, fundamentally alter this
background by reducing the amount of information we knew others did not
know about us. Two things would happen as a result. First, many people
would be disadvantaged in ways they would not be if the device did not exist.
Newspaper and magazines could—and no doubt some would—discover and
publish the names of rape victims and thereby cause them great emotional
distress. Employers would discover their potential or current employees’
political affiliations, sexual preferences, past crimes, and the like, and refuse
to hire them or fire them as a result. Most will deplore the publication of the
rape victims’ names; what an employer is entitled to know is, on the other
hand, considerably more controversial. There would also be a second result,
and this is the result I want to emphasize here. In doing so, I by no means
intend to minimize the harms that the disclosure of personal information may
cause; however, many have already emphasized this point. The second
result would be a fundamental change—for better or worse—in our relations
with each other. Those relations are premised in part on what we know
others do not know about us. Change that background knowledge, and you
alter the relationship. This is the point of the Brian/Brianna example.
Suppose that Brian never does use the JulesVerne-O-Scope to view Brianna’s
past; nonetheless, Brianna’s suspicion destroys her prior confidence that
Brian did not know certain things about her and replaces it with distrust,
fear, and resentment. The effect need not be so corrosive, of course.
Brianna might react by ceasing to care so much about what others think of
her and, as a result, enjoy a new-found sense of peace. But the point still
stands: change the background knowledge, and—for better or worse—you
change our relations with each other.
The JulesVerne-O-Scope does not exist. But computers, databases,
and the Internet do. Advances in surveillance techniques allow us to collect,
search, and analyze vast amounts of information, and the Internet worldwide
distribution. Does the availability of this information amount to something
akin to a JulesVerne-O-Scope? If so, what will the effect be on the
background of knowledge against which we conduct our relationships with
others?
It helps here to borrow the game-theory concept of common
knowledge. Something is common knowledge between you and me when
(and only when) we know it; we know we know it; we know we know we
know it; and so on. Suppose, for example, that you and I make eye contact;
we see each other seeing each other and hence know that we are making
eye-contact; know that we know; know that we know that we know, and so
on. In general, shared culture, education, and experience create a great deal
of common knowledge. It is common knowledge among most U. S. citizens
that George Washington was the first president of the United States. It is
common knowledge between you (as the reader of these words) and me (as
their writer) that these are English words. It is possible to redescribe the
Brian/Brianna example in terms of common knowledge. It is—absent the
JulesVerne-O-Scope—it is common knowledge between Brian and Brianna
that Brian knows neither the top price she is willing to pay, nor her feelings
about her marriage. The Brian/Brianna example illustrates the general point
that we conduct our relations with others against a background of shared
knowledge of the limits of our knowledge of each other. Recast in terms of
common knowledge this becomes: we conduct our relations with others
against a background of common knowledge of the limits of our knowledge of
each other.
The advantage of the common knowledge redescription of these facts
is that it provides a broader context in which to set the fact that our relations
with others proceed against a background of shared knowledge of the limits
of our knowledge of each other. Common knowledge plays a role in a wide
range of activities; indeed, as Peter Vanderschraff and Giacomo Sillair
emphasize,
[c]ommon knowledge is a phenomenon which underwrites much of
social life. In order to communicate or otherwise coordinate their
behavior successfully, individuals typically require mutual or common
understandings or background knowledge. . . . If a married couple are
separated in a department store, they stand a good chance of finding
one another because their common knowledge of each others' tastes
and experiences leads them each to look for the other in a part of the
store both know that both would tend to frequent. Since the spouses
both love cappuccino, each expects the other to go to the coffee bar,
and they find one another.1
Prior to the JulesVerne-O-Scope, Brian and Brianna coordinated also
coordinated their actions in light of their common knowledge. The
JulesVerne-O-Scope destroys the coordination by destroying the common
knowledge. Lack of common knowledge often causes lack of coordination.
Vanderschraff and Giacomo Sillair offer the example of “a pedestrian
[who]causes a minor traffic jam by crossing against a red light . . . [She]
explains her mistake as the result of her not noticing, and therefore not
knowing, the status of the traffic signal that all the motorists knew. . . .
[T]he pedestrian and the motorists miscoordinate as the result of a
breakdown in common knowledge.” 2
One well-known point about common knowledge is particularly
important here: namely, doubt can easily undermine common knowledge.3
This is what happens in the Brian/Brianna example. Brianna begins to
wonder—with some justification, let us suppose—whether Brian is using the
JulesVerne-O-Scope to view her past, and, as result, she is no longer sure
that he does not know, for example, the highest price she is willing to pay
and her feelings about her marriage. She does not know that he does know;
she just doesn’t know that he does not. She is just in doubt. The doubt is
enough, however, to undermine the prior common knowledge about the
limits of what they knew about each other.
This brings us back to computers, databases, and the Internet. The
digital and Internet revolution make vast amounts of information about
people readily available worldwide. One thing seems clear: a profound
change—for the better or worse—is already underway. Consider Facebook.
Eight out of ten college students belong to Facebook, and the site draws
250,000 new members a day.
[M]ore than 60 percent of Facebook users posted their political views,
relationship status, personal picture, interests and address. . . . People
also post a whopping 14 million personal photos every single day,
making Facebook the top photo website in the country. Then users
diligently label one another in these pictures, enabling visitors to see
Peter Vanderschraff and Giacomo Sillair, Common Knowledge,
http://plato.stanford.edu/entries/common-knowledge.
2
Peter Vanderschraff and Giacomo Sillair, Common Knowledge,
http://plato.stanford.edu/entries/common-knowledge.
1
Michael Chwe, Structure and Strategy in Collective Action, 105 AMERICAN JOURNAL OF
SOCIOLOGY 128 (1999); Michael Chwe, Communication and Coordination in Social
Netoworks, 67 REVIEW OF ECONOMIC STUDIES 1 (2000); MICHAEL CHWE, RATIONAL RITUAL
(2001).
3
every photo anyone has ever posted of other people, regardless of
their consent or knowledge. . . . Facebook's 58 million active members
have posted more than 2.7 billion photos, with more than 2.2 billion
digital labels of people in the pictures.4
The default setting (which most users leave unchanged) makes posted
information available to any other member of the Facebook network.
Social networking sites like Facebook show that people (at least the
younger generations) willingly share personal information with strangers.
The result is a profound change in the common knowledge background.
Where strangers have ready access to your personal information, you do not
know what they know about you. They may know all the posted details, or
none of them. Is this change for the better or the worse?
Ari Melber, About Facebook, THE NATION,
http://www.thenation.com/doc/20080107/melber
4