账户 and device

Three doors

Imagine a house. The lock on the front door is not the same as the key to a locker at school. And a locker at school is not the same as a vault at a bank. On the internet it is similar. You have three doors. When you lock one, the others can stay open.

1. Phone — lock (PIN, fingerprint, face). Whoever unlocks it is in the apps. They see chats, photos, saved accounts.
2. Computer — sign out when it is not yours. A school classroom is not your room. A family laptop in the living room is not only yours either.
3. 账户 — school email, Google, a game. The account password is not the phone lock. They are different keys.

You can have a locked phone and still an open school account in the browser on someone else’s computer. That is why you sign out. The phone lock watches a bit of metal in your pocket. The account watches your name at school, in the cloud, in the classroom.

When you mix up these three doors, an ordinary thing happens: you leave the computer, a friend finishes “your” homework, the teacher sees you. Or the other way: you lend an unlocked phone “just for a minute” and someone opens school mail.

How it looks in practice

学校 classroom. You sign in to the school account. The bell rings. You run to lunch. The browser stays open. Next lesson, another class, another person in your chair. They see your name in the top right. That is not an evil attack. That is a forgotten sign-out.

Sofa at home. A sibling borrows the tablet. You are still signed in to the game and to school. They click somewhere else. Then you look for “who sent me that”.

Someone else’s wifi in the library. You open school on a computer lots of people use. Even if you are polite and leave nothing on the desktop, the account in a browser tab waits for the next person.

So you have one reflex: it is not my device → I sign out.

1. On a school or family computer, open the account you use for school.

2. Find your icon (top right). Click 退出登录. Check that instead of the name there is a 登录 button again.

3. On the phone: Settings → lock. If there is no lock, switch it on with a parent. Do not leave the PIN as 0000 or a year of birth. Not 1111. Not four of the same digit.

What to say when someone asks you to unlock

Short sentences. No apology that you are “paranoid”.

A classmate at the computer:

“This is a school account. I will sign out. 登录 with yours.”

A sibling with the phone:

“I am leaving the lock on. If you need to call, tell mum.”

A friend: “Just a second, I know the PIN.”

“I do not lend the PIN. Same as the key to the flat.”

You do not need to explain the whole course. No is enough. If they keep pushing, that is a signal for an adult, not for a longer debate.

A phone lock is politeness, not a punishment

Some children hear: “The lock is because we do not trust you.” We take it differently. The lock is because a phone can do a lot at once: chat, photos, school, a map of the house. If someone picks it up from the desk, they should not walk inside.

With a parent, pick a way you actually use:

• A PIN that is not a date.
• Fingerprint or face, if the phone can do it and a parent agrees.
• A longer code if you tend to forget a PIN — a parent has it in the vault, not you in chat.

A lock the whole class can open is not a lock. It is a hello.

A school account and a game account are two people

A school account carries your name, class, homework, marks. A game account carries a character, a skin, friends from the lobby. When you mix them into one login, one mistake hits both.

The rule is boring and good: school = school door. Game = game door. 开始 a new game with a parent, with a different email or a family account that belongs to that. Do not paste the school address in “because I know it by heart”.

This also helps with the project 👤 Safer profile. A game profile does not need the school name, a surname or a street. A nickname is enough.

What if I forget to sign out

It happens. The bell rings. You run. The chair is empty. When you remember, go back if you can. Signing out later is better than “not dealing with it”. If someone else is already sitting there, tell the teacher: “I left an account open. I need to close it.” That is not embarrassing. That is tidying up.

It holds on a family tablet too. A shared device either has a sign-out after each person, or accounts a parent set up. “We are one family” is not a reason to leave school mail open on the sofa.

A 铬色book at school often signs the school account out on its own when you close it. Still check the name in the top right before you leave. The reflex is faster than guessing “whether this model can do that”.

If you find someone else’s name on the computer, do not sign it out blind when you do not know whose it is — call the teacher. Someone else’s account is not your toy. Same as someone else’s locker.

Mini audit: three lines on paper

This is the start of the project 📱 Phone audit. You are not deleting apps yet. You are only writing down what is there.

With a parent, write three lines on paper (not in chat, not on Discord, not in a shared class document):

• phone — lock yes/no, it is not a date
• school account — who knows the password (you + a parent, nobody else)
• someone else’s computer — I sign out

The paper belongs in a drawer with a parent. You do not have to photo it into the gallery. The gallery backs up. The drawer does not.

Now you 💪

Do those three lines on paper. Then actually sign an account out once on a device that is not only yours. So the hand knows where to reach when the bell rings.

1. Find the account icon. 退出登录. Check that the name disappeared.

2. With a parent, open the phone lock. If it is a year of birth, change it. Say the new code out loud only to a parent. Do not write it anywhere on this page, in chat or in a notebook on the desk.

3. When you have the paper, add one sentence to family rules: On someone else’s computer we sign out. A school account is not a game account.

What to take from this lesson

• A device and an account are different doors.
• 退出登录 on someone else’s computer. Always.
• A school account is not a game account.
• A PIN is not a date, 0000, or “what the whole class knows”.
• Three lines on paper = the start of the phone audit.

© 2026 Ing. Martin Polak / AlgoRhino · 内容使用条款