The Logic of Privacy on Facebook


	Me	Friends	Friends of Friends	Friends of Person Tagged	All of Facebook
Profile Picture	Visible	Visible	Visible	Visible	Visible
I posted, nobody tagged	Visible	Not Well Defined	Not Well Defined	Not Applicable	Not Well Defined
I posted, tagged a friend	Visible	Not Well Defined	Not Well Defined	Not Well Defined	Not Well Defined
Friend posted, I'm tagged	Visible	Not Well Defined	Not Visible	Not Well Defined	Not Well Defined
Photo of me, posted by anyone	Not Well Defined	Not Well Defined	Not Well Defined	Not Well Defined	Not Well Defined

What is the audience on your post?

What is the audience you have chosen to add to posts you're tagged in?

What is the audience on your friend's post?

What is the audience your friend has chosen to add to posts they're tagged in?

(For fun) Do you have a Facebook?

Is your facial recognition setting on Facebook turned on?

% STYLING THE CHART
%:- holds(A,B,C) & post_type(A) & audience_type(B) & viz_type(C)
innerhtml(chart(A,B), Str) :- post_type(A) & audience_type(B) & holds(A,B,C) & viz_type(C) & tostr(C,Str)

style(chart(A,B),background, "#ececec") :- post_type(A) & audience_type(B) & holds(A,B,not_applicable)
style(chart(A,B),background, "#fffec8") :- post_type(A) & audience_type(B) & holds(A,B,visible)
style(chart(A,B),background, "#b7ffbf") :- post_type(A) & audience_type(B) & holds(A,B,not_visible)
style(chart(A,B),background, "#ffdc97") :- post_type(A) & audience_type(B) & holds(A,B,depends_others)
style(chart(A,B),background, "#ffaaaa") :- post_type(A) & audience_type(B) & holds(A,B,undefined)

innerhtml(title(A), Str) :- question(A, B, Str)

% HANDLING DEFAULTS
load:: default(A,B,C) ==> holds(A,B,C)
load:: default(A,B) ==> value(A,B)
load:: question(A,select_audience,C) ==> value(A,fb_unknown)

click(apply_defaults):: fb_audience(D) & distinct(D, fb_friends) ==> value(your_post_audience, fb_friends) & ~value(your_post_audience, D) 
click(apply_defaults):: fb_audience(D) & distinct(D, fb_friends) ==> value(your_tagging_audience, fb_friends) & ~value(your_tagging_audience, D) 
click(apply_defaults):: fb_audience(D) & distinct(D, fb_friends) ==> value(friends_post_audience, fb_friends) & ~value(friends_post_audience, D) 
click(apply_defaults):: fb_audience(D) & distinct(D, fb_friends) ==> value(friends_tagging_audience, fb_friends) & ~value(ffriends_tagging_audience, D) 
click(apply_defaults):: value(facial_recog, yes) & ~value(facial_recog, no) 
click(apply_defaults):: value(on_fb, yes) & ~value(on_fb, no)

% HANDLING PRIVACY SETTINGS
select(A, B) :: question(A, select_audience, AB) & fb_audience(B) & fb_audience(C) & distinct(B,C) ==> value(A,B) & ~value(A,C)
select(A, B) :: question(A, yes_no, AB) & yes_no_answer(B) & yes_no_answer(C) & distinct(B,C) ==> value(A,B) & ~value(A,C)

% DEFINING THE LOGICAL RELATIONSHIP BETWEEN SETTINGS AND CHART VALUES
% we want to define a series of holds(A,B,C) statements to describe the chart
% A is a post_type, B is a audience_type, C is a viz_type (e.g. visible, not visible, or undefined)
%holds(pbm_ft, me, visible)
%holds(pbm_ft, f, visible) :- audience_selected(q1, fb_friends)

% all entries not defined are "undefined"
holds(A, B, undefined) :- ~defined(A,B)
defined(A, B) :- post_type(A) & audience_type(B) & viz_type(C) & distinct(C, undefined) & holds(A,B,C)

% if you're not on FB, visibility is not applicable for "your" posts, or for PBF_MT
holds(A, B, not_applicable) :- audience_type(B) & post_type(A) & value(on_fb, no)

% PP and CP are visible to everyone 
holds(pp, B, visible) :- audience_type(B) & value(on_fb, yes)
holds(cp, B, visible) :- audience_type(B) & value(on_fb, yes)

% PBM_NT posts are visible depending only on the posts visibility setting
holds(pbm_nt, m, visible) :- value(on_fb, yes)
holds(pbm_nt, A, visible) :- value(your_post_audience, B) & fb_audience(C) & min_notags_fb_audience(A, C) & wider_or_same(B,C) & value(on_fb, yes)
holds(pbm_nt, A, not_visible) :- value(your_post_audience, B) & fb_audience(C) & min_notags_fb_audience(A, C) & wider(C,B) & value(on_fb, yes)
holds(pbm_nt, fopt, not_applicable)

% PBM_FT posts are visible by the group you've selected, plus potentially friends of your tagged friend
holds(pbm_ft, m, visible) :- value(on_fb, yes)
holds(pbm_ft, A, visible) :- value(your_post_audience, B) & fb_audience(C) & min_notags_fb_audience(A, C) & wider_or_same(B,C) & value(on_fb, yes)
holds(pbm_ft, A, not_visible) :- value(your_post_audience, B) & fb_audience(C) & min_notags_fb_audience(A, C) & wider(C,B) & value(on_fb, yes)
holds(pbm_ft, fopt, visible) :- value(friends_tagging_audience, fb_friends) & value(on_fb, yes)
holds(pbm_ft, fopt, not_visible) :- value(friends_tagging_audience, fb_only_me) & value(on_fb, yes)

% PBF_MT posts are visible by the group your friend has selected, plus potentially your friends
holds(pbf_mt, m, visible) :- value(on_fb, yes)
holds(pbf_mt, f, visible) :- value(your_tagging_audience, fb_friends) & value(on_fb, yes)
holds(pbf_mt, f, not_visible) :- value(your_tagging_audience, fb_only_me) & value(on_fb, yes)
holds(pbf_mt, fof, not_visible) :- value(on_fb, yes)
holds(pbf_mt, fopt, A) :- holds(pbf_mt, f, A) & value(on_fb, yes)
holds(pbf_mt, all_fb, visible) :- value(friends_post_audience, fb_public) & value(on_fb, yes)
holds(pbf_mt, all_fb, not_visible) :- value(friends_post_audience, C) & fb_audience(C) & wider(fb_public, C) & value(on_fb, yes)

% POM_AP posts are visible by me only if facial recognition is turned on, and not well defined for any other group
%holds(pom_ap, m, undefined) :- value(facial_recog, yes) 
%holds(pom_ap, m, not_visible) :- value(facial_recog, no)
holds(pom_ap, A, undefined) %:- distinct(A,m)

% MAPPING OUT AUDIENCE RELATIONS
wider(fb_friends, fb_only_me)
wider(fb_friends_of_friends,fb_friends)
wider(fb_public,fb_friends_of_friends)
wider(fb_friends_of_friends,fb_only_me)
wider(fb_public,fb_friends)
wider(fb_public,fb_only_me)
wider_or_same(A,B) :- wider(A,B)
wider_or_same(A,B) :- same(A,B) & fb_audience(A) & fb_audience(B)
%wider(A,B) :- fb_audience(C) & distinct(A,C) & distinct(A,B) & wider(A,C) & wider(C,B) % Couldn't get this working
min_notags_fb_audience(m, fb_only_me)
min_notags_fb_audience(f, fb_friends)
min_notags_fb_audience(fof, fb_friends_of_friends)
%min_notags_fb_audience(fopt, fb_only_me)  % IF YOU ADD THIS YOU NEED TO CHANGE SOME LOGIC ABOVE 
min_notags_fb_audience(all_fb, fb_public)

% ----- RELEVANT SETTINGS AND LINKS TO FB REFERENCE -----

% questions
question(your_post_audience, select_audience, "What is the audience on your post?")
question(your_tagging_audience, select_audience, "What is the audience you have chosen to add to posts you're tagged in?")
question(friends_post_audience, select_audience, "What is the audience on your friend's post?")
question(friends_tagging_audience, select_audience, "What is the audience your friend has chosen to add to posts they're tagged in?")
question(facial_recog, yes_no, "Is your facial recognition setting on Facebook turned on?")
question(on_fb, yes_no, "(For fun) Do you have a Facebook?")

yes_no_answer(yes)
yes_no_answer(no)
tostr(yes, "Yes")
tostr(no, "No")

fb_audience(fb_unknown)
fb_audience(fb_only_me)
fb_audience(fb_friends)
fb_audience(fb_friends_of_friends)
fb_audience(fb_public)
tostr(fb_unknown, "Unknown")
tostr(fb_only_me, "Only Me")
tostr(fb_friends, "Friends")
tostr(fb_friends_of_friends, "Friends of Friends")
tostr(fb_public, "Public")

% ----- AUDIENCE VISIBILITY CHART -----
% post types correspond to the row names on the GDrive Chart prototype
post_type(pp)
post_type(cp)
post_type(pbm_ft)
post_type(pbf_mt)
post_type(pbm_nt)
post_type(pbf_nt)
post_type(pom_ap)
tostr(pp, "Profile Picture")
tostr(cp, "Cover Photo")
tostr(pbm_ft, "Posted by Me, Friend Tagged")
tostr(pbf_mt, "Posted by Friend, Me Tagged")
tostr(pbm_nt, "Posted by Me, Nobody Tagged")
tostr(pom_ap, "Photo of Me, Anyone Posted")

% horizontal axis on chart
audience_type(m)
audience_type(f)
audience_type(fof)
audience_type(fopt)
audience_type(others_fb)
audience_type(all_fb)
audience_type(i)
tostr(me, "Me")
tostr(f, "My Friends")
tostr(fof, "Friends of My Friends")
tostr(fopt, "Friends of Person Tagged")
tostr(others_fb, "Other People on Facebook")
tostr(all_fb, "All People on Facebook")
tostr(i, "The Entire Internet")

viz_type(visible)
viz_type(not_visible)
viz_type(depends_others)
viz_type(undefined)
viz_type(not_applicable)
tostr(visible, "Visible")
tostr(not_visible, "Not Visible")
tostr(depends_others, "Depends on Others’ Settings")
tostr(undefined, "Not Well Defined")
tostr(not_applicable, "Not Applicable")

% default settings? Not sure if this really matters tbh
%default(pp, me, visible)
%default(pp, f, visible)
%default(pp, fof, visible)
%default(pp, fb, visible)
%default(pp, i, undefined)
default(on_fb, yes)
default(facial_recog, no)

% and so on - TODO
% also add colors and styling here perhaps?

% ----- LINKS BELOW -----

% relevant links - audiences
link(pp, "https://www.facebook.com/help/193629617349922")
link(cp, "https://www.facebook.com/help/193629617349922")
link(pbm_ft, "https://www.facebook.com/help/240051956039320")
link(pbf_mt, "https://www.facebook.com/help/323329734435821?helpref=uf_permalink")
link(pbf_mt, "https://www.facebook.com/help/454185581308206")
link(pbm_nt, "https://www.facebook.com/help/120939471321735")
link(pbf_nt, "https://www.facebook.com/help/135566640422874")
link(pom_ap, "https://www.facebook.com/help/135566640422874")
link(audience_type_link, "https://www.facebook.com/help/211513702214269")

% relevant links - questions
link(facial_recog, "https://www.facebook.com/help/122175507864081?helpref=faq_content")
link(your_post_audience, "https://www.facebook.com/settings?tab=privacy")
link(yours_timeline_and_tagging, "https://www.facebook.com/settings?tab=privacy")