1. University of Cologne /
Rheinische Fachhochschule
Cologne
Christian Bosau
Who do you trust: Facebook or your
friends?
Analyzing predictors of privacy protection
in social networks

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Purpose of the study
Main purpose: Looking into trust and the members‘ reaction in social
networks a bit deeper
Aspects about Facebook:
• members are aware of privacy risks (Bosau, Becks & Aelker, 2009; Bosau, Fischer & Koll, 2008)
• still à huge amount of usage
• members try out different protection strategies to lower privacy risks (Young & Quan-
Haase, 2009)
• members restrict their profile (Utz & Krämer, 2009), however mostly to their “friends”-list
The importance of privacy concerns & trust:
• how people generally think about privacy and whether they trust the
requestor influences how much information they give online (Joinson, Reips,
Buchanan & Paine-Schofield, 2010)

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Two agents to be trusted
The platform provider (e.g. Facebook):
• many reports discuss the misbehaviour of Facebook regarding privacy issues
• people know the risk, but don’t care?
The “friends”:
• users add numerous people to their friends-list, even people, that are not close
friends
• managing the increasing number of different kinds of “friends” becomes an issue
Main question: Who is the requestor, i.e. the communication partner in
a social network?

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The study
Method:
• online questionnaire (posted via mailing-lists and personal emails,
snowball sampling) in February/March 2012
• 270 participants
• age: mean=24,8 SD=5,4 male=24%, female=76%
Former studies:
§ measurement of privacy
concerns, privacy protection
behaviour & information
dissemination separately
This study:
§ combining the different
aspects in one single study
§ differentiation between two
trust agents
Research question / hypotheses:
• Trust in Facebook and trust in “friends” are two separate factors.
• Trust in “friends” matters (more than trust in the provider), when it comes to
protecting the privacy in a social network
à dependent variable: privacy protection behaviour in Facebook

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The predictors
Sociodemographic control factors:
Age
General Privacy concern & behaviour (Reips, U.-D., Buchanan, T., & Oostlander, J. ,2008, 2010):
Gender
Attitude
Behaviour
Technical Protection
Behaviour
General Caution
Trust (Joinson, Reips, Buchanan & Paine-Schofield, 2010):
in “friends” in Facebook
Additional predictors:
privacy concerns in FB
(e.g. boyd & Ellison, 2008)
privacy settings of profile
(Utz + Krämer, 2009)
No. of “friends”

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Additional predictors
Specific privacy concerns in Facebook:
• Scale developed based on boyd & Ellison (2008) and Debatin, Lovejoy, Horn &
Hughes (2009)
• Question “Which problems or threats do you see when using Facebook?”
• Scale: 1 = can happen hardly vs. 5 = can happen very easily
• 14 Items (Cronbach’s α = .85):
• Focusing on the major concerns or threats named in the literature:
• e.g. “damaged reputation due to rumors and gossip“; “hacking or identity theft“;
“phishing“; “surveillance-like structures due to backtracking“
“consumer-profiling”
Restrictions & privacy settings set to Facebook profile:
• Scale based on Utz & Krämer (2009)
• Question “Which aspects did you open up to which audience?”
• Scale: “all”, “friends of friends”, “only friends”, “subgroups of friends”, “nobody”
• 14 Items (Cronbach’s α = .83):
• e.g. “name”, “pictures”, “relationships status”, “friends list”, “comments”, “message wall”

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Differences in trust
3,34
2,36
2
2,5
3
3,5
4
trust
in "friends" in Facebook
Trust:
• Scale: 1 = low trust vs. 5 = high trust
• 8 Items (Joinson, Reips, Buchanan &
Paine-Schofield, 2010):
• Focusing on the major
dimensions of trust:
Benevolence, Competence,
Reliability, Integrity, General Trust
• e.g.
„The intensions of ... are good“;
„... is/are trustworthy“;
„... is/are dependable“;
„I felt comfortable giving my
personal information to ...“
• Facebook Cronbach’s α = .83
• „Friends“ Cronbach’s α = .89
F(1) = 297,33; p < .00; η² = 0,52
Important:
§ r = .11 (no sig.)
è no correlation of the two scales
è two independent aspects

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Protection of privacy
Privacy protection behaviour
• based on Young & Quan-Haase
(2009), additional up-to-date
possibilities were added
• Scale: 1 = never vs. 5 = very often
• Cronbach’s α = .83
• 14 items
• e.g.
“I have provided fake or inaccurate
information on Facebook to restrict
people I don’t know from gaining
information about me.”
“I have deleted people from my
friends list.”
“I have told others to delete
pictures that I found unpleasant.”

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Regression analysis
unstandar-
dized B
SE standardized Beta
Age -.00 .01 -.02
Gender .18 .10 .11
• dependent variable: privacy protection behaviour
• stepwise regression analysis
• R2 (adj.) = .13
* p < .05, ** p < .01
Attitude – Privacy Concern .11 .07 .11
Behaviour – General Caution .01 .06 .01
Behaviour – Technical Protection .12 .05 .15*
Trust – in Facebook -.10 .07 -.09
Trust – in “friends“ -.16 .06 -.18**
No. of “friends“ .00 .00 .21**
Facebook privacy concerns -.05 .07 -.05
mean = 3,72 !!

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Regression analysis
unstandar-
dized B
SE standardized Beta
Age -.00 .01 -.03
Gender .19 .10 .12
• dependent variable: privacy protection behaviour
• stepwise regression analysis
• R2 (adj.) = .20
* p < .05, ** p < .01
Attitude – Privacy Concern .11 .06 .11
Behaviour – General Caution -.02 .06 -.02
Behaviour – Technical Protection .10 .05 .13*
Trust – in Facebook -.05 .07 -.05
Trust – in “friends“ -.12 .05 -.14*
No. of “friends“ .00 .00 .21**
Facebook privacy concerns -.05 .07 -.05
Restricted profile .32 .07 .28**

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Conclusion
The “friends” in Facebook are a new important issues
• members are aware of privacy risks, trust in Facebook is quite low
• however, the low trust in the provider does not lead to behavioural consequences
• the huge number of “friends” comprises the risk of not being able to predict the
behaviour of all “friends”
è if members don’t trust their added “friends”, they more likely try to use privacy
protection strategies
è this problem increases with the number of friends
Other results:
• general attitudes about privacy are to abstract and broad to be able to predict
specific behaviour; though, specific Facebook concerns to not lead to protection
either
• there is also a kind of skill or habit factor: if people use technical protection in
other places they do so in Facebook as well
• AND: trust in “friends” and trust in Facebook are two independent factors

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Thank you very much for your attention!
Comments and questions can be sent to:
Dr. Christian Bosau
christian.bosau@gmx.de