The sections before this one looked mainly at what designers, institutions, and governments do. This one turns to the habits of an individual user, which are also what you'll be teaching students. It helps to sort those habits by which way things are moving: what goes out from you, what comes in to you, what passes between you and other people, and finally what your use of technology does to you.

What goes out#

The basic fact about sharing online is that you lose control of it. Online information can be copied, spread beyond its audience, and persist after deletion, so sharing personal details such as photos and full names carries lasting risk. Deleting a post can reduce its visibility, but copies elsewhere may remain, and web archives show how pages outlive changes. Private accounts offer less protection than they appear to, because they limit who sees a post, not what those people do with it: an approved follower can take a screenshot and pass it on.

Given that, the question is which details are risky, and the answer is broader than most students expect. Personally identifiable information (PII) is data that can identify a person, directly (a name or Social Security number) or in combination (a birth date plus a school). The second kind is the one people overlook, since details that seem harmless by themselves can together point to one student. De-identifying means removing direct and combinable details, so taking out a name while leaving a school and a birth date isn't enough. A student asked online for something sensitive, such as a home address, should check with a trusted adult first.

Information can also leave without a person typing it. Metadata is data stored with a file, and photos can record the time and GPS location of capture. Visible details such as a school jacket can reveal more, apart from any metadata, so a single post can disclose where someone lives or goes to school. Turn off location tagging, check backgrounds, and limit location sharing to a few trusted people, reviewing those settings regularly.

An account is another thing students give away more easily than they should. Keep passwords private even from friends, log out of shared devices, and collaborate through sharing features rather than shared accounts, since accounts link actions to a person, and anything done with a student's account will be attributed to that student. A teacher who finds a student's account still open on a classroom computer should log it out and remind the class, without using it.

What comes in#

Just as what you post can travel further than it appears, what you read can be less trustworthy than it appears. Appearance is a poor guide. Polished design, a ".org" address (which almost any organization can register), and a lock icon don't establish credibility. The more reliable method is lateral reading, which means leaving the page to check other trusted sources about a claim or site, rather than judging from its own appearance. It also helps to trace statistics to their source and compare other reports of them. Synthetic media such as deepfakes make outside verification especially important, because a convincing video can no longer serve as its own evidence.

What passes between people#

Online harm is often done by people students know, and it has a recommended response for the student and duties for the school. A student facing cyberbullying should save evidence, not retaliate, use blocking and reporting tools, and tell a trusted adult. Each part of this has a purpose: evidence supports a later report, and retaliation tends to escalate things. A classmate who merely witnesses the harm has a part as well, which is to report the posts and offer support to the targeted student, and not to reply in kind or pass the posts along to others. New York's Dignity for All Students Act requires schools to address harassment, including off-campus conduct that affects the school environment, so the fact that posts were made from home doesn't necessarily take them out of a school's hands. Teachers follow reporting procedures and support the targeted student.

What technology does to you#

The last direction is inward, and it is about well-being more than risk. Healthy use means managing screen time, sleep, and notifications, and noticing how apps affect mood and attention. Practical steps include turning off nonessential notifications, setting a nighttime limit, using a separate alarm clock and charging a phone outside the bedroom, and keeping a one-week log of which apps were used and how each felt. A log like this also reflects a broader point: what someone does on a screen matters along with how long, so a simple total of hours gives an incomplete picture. These habits are part of what any person needs to use computing well, and those who go on to make computing their work need more, as 0001.i describes.

• personally identifiable information (PII): data that can identify a person, directly or in combination
• de-identifying: removing direct and combinable details
• metadata: data stored with a file, such as a photo's time and GPS location of capture
• lateral reading: checking other trusted sources about a claim or site, rather than judging from its own appearance
• synthetic media (deepfakes): realistic generated or altered images, audio, or video
• Dignity for All Students Act: New York law requiring schools to address harassment, including cyberbullying

Practice: practice questions for 0001.h