Exercises: Digital identity

Explain with your own example the difference between digital identity (what you choose to show), digital footprint (the trail left behind even if you do not choose to) and digital reputation (what others conclude from both).

From this list, indicate which data should never be published publicly and explain the risk of each one: your postal address, your favourite team, your ID card number, a photo of your holiday, your timetable and a photo of your face alongside the name of your school.

The figure shows how everyday activity on the internet leaves a digital footprint recorded on a server.

Explain what data remains in the first two cases and what trail would reasonably fill the gap marked with ?. Finish by explaining why that footprint can remain visible years later.

Explain the difference between using your real name, a nickname and an avatar on the internet, what a nickname protects and does not protect, and in which contexts each option is suitable.

When sharing a photo, you do not just share the image: the file contains hidden data that travels with it, as shown in the figure.

Indicate what the data marked with ? reveals, explain what metadata is and why it is advisable to remove it before posting a photo.

Classify these trails into active digital footprint (left intentionally) or passive digital footprint (left unintentionally): posting a photo, the cookies installed by a website, a comment on a video, the route recorded by your phone's GPS. Justify each classification.

"It doesn't matter, it's a story that disappears after twenty-four hours." Explain why a screenshot breaks that supposed security and what you should always remember before posting any "temporary" content.

Choose a famous person (an athlete, a singer, a science communicator) and explain with an invented but realistic example how a controversy from years ago can reappear today in their digital reputation and what tools they have to rebuild it.

A chain message spreads a photo of a classmate without their permission along with taunts. Explain what effect this has on their digital reputation, why forwarding it "without commenting" also contributes to the harm, and what you should do upon receiving it.

List three places online where information about you could appear even if you did not post it yourself (for example, on other people's profiles) and explain what you can do in each case to control it.

A scholarship-granting organisation reviews the public social media accounts of candidates. Explain why what was posted years ago can still appear today and describe two present habits that protect your future reputation.

When searching for your name on the internet, your school's website appears with the list of participants in a competition. Explain whether this poses a problem, what the difference is between your own school posting it or a stranger doing so, and what you could request if you do not want your name to appear.

Parents post daily photos of their ten-year-old daughter with her name, her school and her routines. Analyse what digital identity they are building for her before she can decide, what risks it entails and what reasonable limits you would propose to that family.

An online game asks for your real name "for the global leaderboard". Explain the risks of providing it, what reasonable alternatives exist (nickname, gamer tag) and what you would do if the game made it compulsory.

Explain at least three ways in which a photo uploaded "for friends only" can end up public and what practical conclusion is drawn: does "private" really exist once published?

An internship company finds two trails belonging to the same person: rude comments from three years ago and a current profile that is well-maintained and collaborative. Analyse the impression generated by each trail, whether it is fair to judge someone by their adolescent digital past, and what that person can do today to improve their image.

A classmate tells you: "Yesterday I searched for bicycle shops from my home computer in incognito mode. Today, when I opened a news app on my mobile phone connected to the same Wi-Fi, I got ads for those exact same bicycles. It's impossible for it to be cookies because incognito mode deletes them; the app is listening to me through the microphone!".

1. a) Technically refute their claim: justify why there is no need to activate the microphone and explain two real techniques with which advertising networks could have linked both sessions (for example, correlation via shared public IP address, device fingerprinting, or logging into linked services).
2. b) If your classmate activates a VPN on the computer and browses while blocking third-party trackers, predict whether the advertising company will still be able to immediately associate their web activity with the ads on their mobile phone. Justify your answer.

Analyse this statement: "if you post nothing on social media, you do not have a digital footprint". Reason why this is false even for someone who does not have an account, giving at least two examples of trails that are generated anyway.

Design a profile sheet for a healthy digital identity for the public profile of a teenage athlete: what information to show, what information to hide and what should be reviewed periodically. Justify each decision.

Design a six-step "digital identity audit" that any teenager can perform once a year: what to search for, where to look, what to take note of and what decisions to make with what is found.

At age 14, Tomás committed a minor infraction in a sports competition, and a local digital newspaper published his full name in a report. Today Tomás is 24 years old, is applying for a skilled job, and that news story still appears as the top result when searching for his name on Google.

1. a) Tomás is hesitating between requesting the "right to be forgotten" from Google or demanding that the newspaper delete the article. Justify the technical and legal difference between de-indexing a link on a search engine and deleting the content at the original source.
2. b) Analyze the conflict of rights at play between Tomás's interest (data protection and privacy) and that of the media outlet (freedom of information and newspaper archive preservation).
3. c) Predict what the Data Protection Agency would foreseeably decide regarding Tomás's request to remove the link from the search engine, justifying your answer according to the criteria of the person's current public relevance, accuracy, and the time that has elapsed.

Elena has a private account on a social network with 30 followers (all classmates). She shares an image in her "close friends" section with an offensive comment directed at a teacher, convinced that her audience is completely restricted. Within 48 hours, the image reaches the school leadership team via a family messaging group.

1. a) Model and justify the propagation chain: detail at least three technical or behavioral factors (for example, screenshots, metadata, loss of context in forwards, or automatic cloud backups) by which content in a restricted environment becomes uncontrollable and public.
2. b) A classmate tells her: "Next time, use an app that prevents screenshots or alerts you if someone takes one". Technically evaluate this statement: can an application's software infallibly prevent the copying and dissemination of what is displayed on screen? Justify why digital barriers prove insufficient.

A quiz app ("Which character are you?") asks for a selfie and access to your gallery to function. Analyse what facial and contextual data you are providing, what can be inferred from a face, and why these fun quizzes are such effective data bait.

Some experts propose a "digital age of majority": that content posted before a certain age no longer counts. Argue for and against this idea (maturity, responsibility, right to a second chance) and conclude with your reasoned position.