hi everyone and thanks for attending
this talk I'm going to talk about our
research which is on tracking and
advertising on children website I'm
Zahra a phda student from redb
University and this is a joint work with
my colleague from redb University Ken
and University
B on the modern web trackers and
advertisers often exploit online user um
with online user Behavior without their
content and uh they create a detailed
profile of a user including their
preference and interest for monetizing
users actually for targeted
advertising also there are other kind of
ads that are disturbing in their content
inappropriate and disgusting to to
attract attention a recent research from
University of Washington focused on the
content of the advertisement they
conducted a survey to determine the type
of ads uh that uh people do not like
them and in a later study they uh find a
lot of this inappropriate advertisement
on news and misinformation
websites so while online tracking and
targeted advertising can pose a threat
to the user of all age children are much
more vulnerable uh prior research has
shown that children tend to Mis
misunderstand the message of
advertisement and tend to focus more on
a negative side of the message for for
instance gambling GS and food
advertising but despite the critical
nature of this issue there is uh there
is not a larger scale study focusing on
um website directed at this vulnerable
group so uh to bridge this Gap we
investigated tracking and advertising
practice on child directed
websites of course uh these threats are
are so important that governments around
the world are also trying to take some
serious actions for for instance in the
in the EU uh DSA forbids targeting
children with ads based on profiling or
in the US under Copa data collection for
Target ad advertising on this website is
only allowed after getting uh verifiable
parental consent and actually our study
is timely due to this upcoming and
recent changes in laws that aim to
protect uh children um on the internet
so we wonder what the state of the
targeted and personalized advertising uh
showing to children
now so we conducted this empirical uh
measurement research and we measure
advertise advertisement including uh
targeted and improper
advertisements uh so we focus on U
especially on four categories that PR
research and regulat reports argue that
these categories can be specifically
harmful to Children including dating
Mental Health weight loss and rad we
also uh we also uh detect third party
trackers on children website and also
fingerprinting
attempts in our study we Face some
challenges first of all there is not a
comprehensive and up to- date list of
children website there are uh some uh
list including a few uh a few children
website which are were handpicked by
expert uh but they're not enough for
larg scale study and uh another
challenges that we faced was um
detecting advertisement especially
targeted and improper ads automatically
and to do so we needed to scrape adds
and a disclosure
page so to overcome the first challenge
we built our own repository of children
website um using uh this existing list
and also online categorization Services
we built a machine learning classifier
that detect children website based on
their title and uh metadata such as
description then uh we applied this
classifier to a to a very large data set
of website content uh including several
billions of several billion pages cwed
from the web to identify this website
and since we wanted to have a reliable
and robust list of um list of children
website we conducted a manual review to
remove uh false positive and speaking of
the classifier we use an existing model
a prein model that use um that was
trained on a on a huge data set of texes
with a billions of parameter but there
uh there are some small models called
distill model a tiny and efficient model
that learned that learned from a very
large teacher model and they can distill
the knowledge of bigger model and with a
comparable accuracy
and also uh the model that we picked was
multilingual it support uh around 50 uh
50 different languages then we could
detect uh children website on different
languages after preparing the data set
for crawling process we utilize an
existing open source crawler but uh we
modified it heavily uh our crawler is an
extended version of tracker Rider
collector which is a web crawler
developed by uh Dr go uh the scrawler
interacts with the web page and records
different type of um data during the CW
specifically add related uh and add
disclosure data uh fingerprinting
related function called um HTP request
respond and Etc and it also can record a
video of the
recording uh with this study we measured
whether at targeting is enabled or Not
by by scraping at disclosure page to
accomplish this our interactive C our
interactive crawler first detect and
scrape advertisement and then it clicked
on the add disclosure button and scraped
the information from a disclosure page
and later uh we uh we use this
information to determine if um ad
targeting or ad personalization is
enabled for that that specific website
or
not uh we then of crawler uh to craw
children website from different Vantage
points to EU City uh like uh frankurt
and Amsterdam one non City like London
and two City from from us New York City
and San Francisco we also did a limited
measurement on mobile to see how ads
change when using mobile
um so this data are uh this data is
based on more than uh more than 70
20,000 Pages uh collected from 2,000 uh
websites and we also take five inner
pages from each website uh it was the
scroll is not are not just based on uh
homepages okay now let's uh let's turn
to the finding of our
study here is an overview of our result
our CER scrape more than 70 uh 70,000
advertisement from 8004 different uh
children websites and we found the
advertisement on 36% of this we websites
and more importantly on average 27% of
this website contain targeted
advertisement a practice which is
restricted or Bann based on U regulation
or policy and over 70% of this um
advertisement that we capture are
targeted uh meaning that they enable
build ad targeting or ad personalization
so non-targeted ad or minority even for
for children website uh we also did a
exploratory analysis of whether ads on
child directed website link to a
malicious page or not uh we took a
sample and um we found uh 150 out of
4,000 scan link uh that they were
flagged as a malicious or fishing by at
least one um scan engine uh from uh
virus total
you might wonder who are this website
that are showing Target advertisement to
Children um here in this plot you can
see the popularity rank of this uh this
website and actually this is one of the
positive finding of our studies and um
as you can see in the pinkish bar the
more popular the website is the more
likely to show non-targeted ads to
children so uh top uh top websites the
more popular we website turn of AD
personalization uh more often than low
traffic
websites uh we also looked into the
content of the advertisement including
text and images to detect improper ads
there are some specific category that
should not occur on children website per
policy or regulation like um dating
racing Etc to identify ads containing
clickback Ry content uh we use the
Google Cloud Vision API Ser search
detection and in addition uh using the
multilingual model that allowed us to
query for some Search terms like uh
dating Etc uh and it Returns the related
um related um related ads to those
Search terms the actually the model
captur semantic similarity between the
Search terms and uh Tes extracted from
advertisements and it can also be used
for other for other categories and at
the end we did a manual you to remove
the false
positives uh this table shows the number
of number of improper advertisement we
identified in uh in each CW uh amounting
to more than thousand improper
advertisement across 311 distinct
websites children websites and uh we
stop manual review after reviewing
thousand ads for each uh for each
categories so these uh numbers are lower
but uh just to to have a sense of
whether uh this improper ads exist on
children website or not and
unfortunately they
do now I'm going to show you some images
uh we uh that we found in our study that
are not safe for
work these are some samples of improper
ads we detected on children website uh
we found ads related to weight loss
mental
health race as and etc for instance uh
figure B features an image um image of
ice cream that uh that could be
appealing to children
but uh this is an advertisement about
largest online uh sex toy shop in
Germany uh the other one in figure a uh
is an advertisement from Alibaba uh
display adds featuring racing and this
there being and the stateful images to
IM um images of product sold on Alibaba
alibaba.com and uh these are mostly for
grabbing
attention we uh manually visited some of
these websites showing targeted
advertisement from our computer to see
if uh still we can we can find this
improper ads or not for example here in
this website um like uh which is a uh Vu
uh junior which is a kids activity
obviously for children you can see this
advertisement here in the the bottom of
the page uh which is written in Dutch go
never go to bed alone but it's a flirt
finder it's scams and AI
chatbot or in another example um that we
found in a website uh which is for for
for children like uh to to uh to learn
count numbers to 20 and this kind of a
stuff we found this amig Gates which uh
which are most of the time
scammy or in another website including
Kinder Garten material uh we detect this
um this improp advertisement here
again uh you might wonder who are this
advertisers uh in that disclosure
interface you can also see advertisers
identity actually Google tells you uh
this ad is run by company but but this
is not not for all ad this is just for
some of the ads and as you can see here
in this table advertisers from uh other
part of the world uh like from Cypress
or United Arabic Emir or is like isra
are showing ads uh to children in the EU
or in the US visiting this
website uh we also compare trackers and
website with with advertisement and
without advertisement if a website has
ads uh there is a lot of tracking going
on and also we we compare trackers
between um the EU and US CR and as you
can see in this figure there are more
tracker on on us on us visit so more
tracking on a US visit more tracking on
um on website uh with
advertisements uh this table shows uh it
with the most number of distinct
trackers uh for example in the New York
City Crow uh visiting a website like
Masson work.com we found 161 distinct
third party trackers in just one in a
single website uh whereas in the EU uh
visiting W space.com it trigger 95
distinct trackers which is uh less than
the US SC but still it is a
lot so we reached out to five companies
that we found uh to serve RAC as uh one
of these companies invited us to a call
and explain the likely reason for
showing inappropriate advertisement and
uh indicate that they will uh they will
make further
investigations uh we also disclosed 34
racy ads to Google by manually visiting
the ad disclosure URL of each RAC ad uh
using the report this uh report this ad
button uh in addition we shared our
results with the with uh European data
protection agencies uh consumer data uh
consumer protection agencies and a UK
based NGO focusing on uh children
digital rights and lastly our paper will
be present on U Kel's uh privacy
research Day on on
Paris so to sum up uh our study reveals
the extensive tracking and frequent
targeted and improper advertising on
children website we found that popular
websit are less likely to use targeted
ads and uh we call for more research
regulation and enforcement uh to protect
children on privacy online um and lastly
our source code and data is open source
on GitHub uh make sure to check it out
and thanks for attending this St and
feel free to reach out if you have any
questions