Data Collection
How are digital footprints created?
Web Bugs
What are web bugs?
These are small objects embedded into a web page, but are not visible. They can also be known as "tags", "tracking bugs", "pixel trackers" or "pixel gifs".
How do web bugs track you?
A simple version of this is a tiny clear image that is the size of a pixel. When a web page with this image loads, it will make a call to a server for the image. This "server call" allows companies to know that someone has loaded the page.
This is very useful to companies that want to learn if readers are opening their the emails they send. When the web beacon loads, companies can tell who opened the email and when.
This system has been abused by spammers who will identify active email accounts by sending emails that include pixel trackers. This is why many email systems will ask if you trust the sender before it displays images.
JavaScript
What is JavaScript?
JavaScript is a programming language for the web. It is supported by most web browsers including Chrome, Firefox, Safari, internet Explorer, Edge, Opera, etc. Most mobile browsers for smart phones support JavaScript too.
How is JavaScript used to track you?
JavaScript is a major tracking tool. A browser will run any JavaScript code
found in the original HTML file or loaded from a URL with
src="name.js" in a script tag. This is heavily used for “analytics” that try to measure
how particular pages are viewed.
JavaScript code can set and retrieve cookies from the site that the
JavaScript itself came from, and can access other information like the
browser’s history of pages visited. It can also monitor the position of your
mouse continuously and report that back to a server, which can infer what
parts of the web page might be interesting or not; it can also monitor places
where you clicked even if they weren’t sensitive areas like links. JavaScript
tracking appears to be increasing.
Browser Fingerprinting
What is browser fingerprinting?
Browser fingerprint is information collected about a remote computing device for the purpose of identification.
Fingerprints can be used to fully or partially identify individual users or devices even when cookies are turned off.
How is browser fingerprinting used to track you?
Browser fingerprinting uses individual characteristics of your browser to
identify you, often uniquely, without cookies. The combination of operating
system, browser, version, language preference, and installed fonts and plug-
ins provides a lot of distinctive information. Using new facilities in HTML5,
it’s possible to see how an individual browser renders specific character
sequences, using a technique called canvas fingerprinting. Given a handful of
these identifying signals, it’s possible to distinguish and recognize individual
users regardless of their cookie settings. Naturally advertisers and other
organizations would love to have pinpoint identification of individuals
regardless of cookies.
GPS
What is GPS?
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Air Force.
It is a global navigation satellite system that provides geolocation and time information to a GPS receiver anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites.
How is GPS used to track you?
A GPS-enabled phone, which includes all smartphones, generally knows
where you are to within about 10 meters when you’re outside and can report
your position at any time. Some digital cameras include GPS as well, which
lets them encode the geographic location in each picture they take; this is
called geo-tagging. Newer cameras have Wi-Fi for uploading pictures; there’s
no reason it couldn’t be used for tracking as well.
When tracks like these are collected from multiple sources, they paint a
detailed picture of our activities, interests, finances, associates, and many
other aspects of our lives. In the most benign setting, that information is used
to help advertisers target us more accurately, so we will see advertisements
that we are likely to respond to. But the tracking need not stop there and its
results can be used for much less innocent purposes, including discrimination,
financial loss, identity theft, government surveillance, and even physical
harm.
Social Media
What is social media?
Social media refers to websites and applications that are designed to allow people to share content quickly, efficiently, and in real-time.
How is social media used to track you?
Geolocation services display their users’ locations on cell phones, which
makes it easy to meet friends in person or to play location-based games.
Targeted advertising can be especially effective when a potential customer’s
physical location is known.
Location privacy —the right to have your location remain private—is
compromised by systems like credit cards, toll payment systems on highways
and public transport, and of course cell phones. It’s harder and harder to
avoid leaving a trail of every place you’ve ever been. Cell phone apps are the
worst offenders, often requesting access to essentially everything that the
phone knows about you, including call data, physical location, and so on.
Does a flashlight app really need my location, contacts and call log?
Cookies
What are cookies?
Cookies are small bits of text that are downloaded to your browser as you surf the web. Their purpose is to
carry bits of useful information about your interaction with the website that sets them.
Cookies generally do not contain any information that would identify a person. Usually they contain a string
of text or "unique identifier". This acts like a label. When a website sees the string of text it set in a
cookie, it knows the browser is one it has seen before.
How do cookies track you?
The cookies that appear to cause the most controversy are for managing the advertising you see on a website.
This is particularly the case when websites set a cookie from a separate advertising delivery company. This cookie can record when and where you saw an advert, where in the world you might have been when it happened and whether you clicked on it.
The cookie will send this information to the cookie owner, who records this data and uses it to make sure you don't see the same advert too many times.
If websites choose to pool some of the information this type of cookie collects as part of an ad network, the systems used by advertising delivery companies can create "segments" of browsers that display similar behaviours.
They will use this to try to draw conclusions about what the people behind the browsers might be interested in: "basketball lovers" or "hair product enthusiasts" or "adventure holiday takers", for example. Cookies that do this are known as third-party advertising cookies.
Over time they learn which types of adverts are most effective to these groups and can sell this service to advertisers.