A perfectly normal Tuesday with four messengers

Nothing to hide? Neither have I. But would you write your mobile number on a slip of paper for the entire nursery parents’ group? Or tell a stranger that your child had a fever last night?

Take a perfectly normal Tuesday. Your Tuesday: nursery, work, the paediatrician, a traffic jam, dinner. You live through it four times, with four different messengers. Once with WhatsApp, once with Signal, once with Telegram, once with Threema. The messages are the same each time. What the provider knows about you by the evening differs from app to app.

According to Bitkom, 85 per cent of internet users aged 16 and over in Germany use WhatsApp, 22 per cent Telegram, 14 per cent Signal and 6 per cent Threema. What the same day looks like with an Android phone and with an iPhone is covered in the first two parts.

01The evening before

The nursery has a parents’ group. To join it, you need the app.

With WhatsApp you enter your mobile number and a name. Anyone who has your number can look up your profile picture and your “About” text unless you restrict it. Usernames are meant to change that. On 14 October 2026 the app offered to reserve one in advance: it is meant to hide your number from people who do not already know it. Instead of making up a new one, you can also take over your name from Instagram or Facebook.

With Signal you also need your number. Since February 2024, however, others no longer see it unless they already have it. Your name and profile picture cannot be read by Signal itself.

With Telegram you need your number and, in Germany, one euro. Telegram charges it as an “SMS fee”, citing “many fake accounts and high SMS costs in your country”. We tried it on 14 October 2026 and did not pay. Your name and profile picture are always public on Telegram. In the EU you may only use it from the age of 18; nobody checks.

With Threema you need neither a number nor an email address. You get a random eight-character ID. In return, the app costs a one-off fee.

You only wanted to be able to message the other parents.

026:47 The alarm goes off, three messages are waiting

You reach for your phone. Three new messages, all from overnight.

With all four a notification from Google or Apple wakes the app. On Android, Signal and Threema send an empty message for this. Google or Apple still see when your phone was woken. Authorities ask for exactly that. How it works without Google is shown in the GrapheneOS Tuesday.

With WhatsApp WhatsApp now knows when you go online, which phone you have, how full your battery is and how good your signal is. From your internet address and your dialling code, WhatsApp estimates roughly where you are.

With Signal Signal stores, by its own account, the day you last connected. No time of day. Signal does not say whether it keeps your internet address.

With Telegram Telegram keeps your internet address, your devices and your apps for up to twelve months. Others can also see when you were “last seen” unless you switch it off.

With Threema Threema stores the date you last logged in. Again without the time. According to Threema, your internet address is used only during transmission.

You only wanted to switch off the alarm.

037:30 Nursery, the parents’ group

You drop your little one off at nursery. On the way back to the car your phone beeps. The parents’ group: “Don’t forget the wellies, it’s forest day tomorrow!” There are 23 parents in it; most of them you only know by sight.

With WhatsApp all 23 now have your mobile number, including the father you have never exchanged a word with. WhatsApp cannot read what you write. It can see what the group is called and which picture it has (as of 2021).

With Telegram Telegram can read everything: the wellies, the birthday party invitation, the photo from the lantern parade.

With Signal or Threema the provider does not even know that the group exists.

You were only being reminded about the wellies.

048:15 The fever photo to your friend

Your little one was very warm last night. You send your friend a photo of the thermometer: 38.4. “Do you think I should see a doctor?”

With WhatsApp WhatsApp cannot see the photo. But WhatsApp records when you write, how often and for how long. And in the US, WhatsApp has supplied authorities, on court order, in real time with who is messaging whom. How that works is explained in the Meta Files on WhatsApp.

With Signal Signal cannot see the photo either. If you have saved each other as contacts, Signal usually only knows who the message is going to, not who it is from.

With Telegram the photo sits readable on Telegram’s servers until one of you deletes it. It would only be protected in a “Secret Chat”, which you have to start separately.

With Threema Threema cannot see the photo. It only stays on the server until your friend has collected it, for 14 days at most.

You only wanted to know whether 38.4 is already bad.

059:00 The new babysitter

Your neighbour gave you a number. You save it: “Jana Babysitter”. On Friday the two of you want to go to the cinema again.

With WhatsApp WhatsApp regularly checks your address book. Your grandmother’s number is in it too, and she does not even have WhatsApp. WhatsApp stores her number in converted form and links it to everyone who has saved it. Europe’s data protection authorities consider this form personal data as well.

With Telegram Telegram stores the number and the name exactly as you typed it: “Jana Babysitter”. Even if Jana has never used Telegram.

With Signal the check runs in a sealed-off area of the server. Afterwards, by its own account, Signal keeps none of it.

With Threema the check only happens if you switch it on. Afterwards Threema discards the data immediately.

You only wanted to go to the cinema on Friday.

0612:15 Lunch break, a quick look at the channels

Five minutes of peace. You scroll through the parenting tips channel and the news.

With Telegram you see adverts in between. Since 21 August 2026, Telegram has targeted them by the city you are in and the kind of channels you read. Anyone who pays for Premium sees none.

With WhatsApp Meta has announced for the EU adverts in the “Updates” tab, tailored to country, city, language and the channels you follow. According to Meta, your chats are not used for this. In our test on 14 October 2026, WhatsApp only advertised itself there.

With Signal or Threema there are no adverts. Signal lives on donations to a foundation, Threema on sales of the app and business customers. Since January 2026, Threema has belonged to the Frankfurt investment firm Comitis Capital.

You only wanted to switch off for five minutes.

0714:00 The paediatric practice gets in touch

“Your results are in. Please call us between 3 and 4 pm.” The practice now uses a messenger as well.

With WhatsApp this message is protected differently from the one to your friend. If the practice writes via a service run by Meta, the chat is not end-to-end encryptedend-to-end encryptedOnly sender and recipient can read the message. The provider passes it on but has no key to it. according to WhatsApp, Meta manages the keys on the practice’s behalf and may keep the messages for up to 30 days. A notice in the chat shows this.

With Threema it is similar if the practice writes via Threema’s business offering. Depending on the variant, messages are decrypted on Threema’s server. If the practice saves the history, they stay there for up to 180 days.

With Telegram the practice may be writing via a botbotA program that replies in a messenger like a chat partner. It is run by a company or individual, not by the messenger itself.. Then whoever runs the bot reads along. Telegram can read the chat anyway.

With Signal we found no offering for businesses. There is a warning all the same: the real Signal support never messages you, Germany’s BfV and BSI warn. Anyone using that name wants access to your account.

You were only supposed to call back.

0817:00 Calling your mother

You call your mother. You tell her about the fever and the results. Nothing to worry about.

With all four nobody listens in, not even the provider. Many calls, however, run directly from phone to phone. Your caller then sees your internet address and can roughly tell where you are and which provider you use.

With WhatsApp there is a “Protect IP address in calls” switch for this. It routes calls via WhatsApp’s servers. It is off by default; you have to switch it on yourself.

With Signal it is called “Always relay calls” and sits in the advanced settings. Signal itself notes that call quality suffers. On our phone it was switched off.

With Telegram calls between contacts run directly, and both see the other’s address. If a stranger calls you, it goes via Telegram’s servers. This can be changed under “Privacy”, “Calls”.

With Threema calls always run via the server until you have verified the contact in person.

With your mother it does not matter. With the father from the nursery group who calls you, it may.

You only wanted to reassure your mother.

0918:00 Stuck in traffic

Nothing is moving on the motorway. You send your partner your location so they know you will be late.

With WhatsApp the location is encrypted, even if you share it live. WhatsApp estimates roughly where you are from your internet address anyway.

With Signal you can only send your location once. Live sharing is not possible; we checked on 14 October 2026.

With Telegram the location in a normal chat sits on Telegram’s servers like any other message. If you share it live, it keeps running even when the app is closed.

With Threema the location is encrypted. On Android the map comes from Threema’s own servers, not from Google.

You only wanted to say you would be late.

10At night: the phone backs itself up

The phone is on the charger. Some time after midnight it makes a backupbackupA copy of your chats, usually in a cloud such as Google Drive or iCloud, so they are not lost when you get a new phone..

With WhatsApp your history ends up in Google Drive or iCloud. It is only encrypted there if you switch that on yourself. We only found the switch via the “Privacy checkup”. After that, according to WhatsApp, “not even Google or WhatsApp” can access the backup. If you forget the password and lose your phone, however, it is gone. With iCloud, Apple holds the key unless you use Advanced Data Protection. And if your friend backs up unencrypted, your fever photo sits in her cloud.

With Signal backups have been possible on all devices since September 2026 and are encrypted; only you have the key. If you lose it, the backup is gone. The FBI warns of fraudsters posing as support to get hold of exactly this key.

With Telegram no backup is needed. Your chats sit permanently on Telegram’s servers anyway.

With Threema “Threema Safe” backs up your contacts and groups, encrypted with your password. Your messages are not included.

You only wanted to make sure the photos of the children are not lost.

11Three weeks later: the police make a request

This part is made up. What the providers hand over is documented.

The police are investigating a father from the nursery group. Not you. They send a request to the provider. What phone and internet providers in Germany are to store anyway is covered in our article on data retention (in German).

With Signal they get two pieces of information: when the account was created and on which day it last connected. Signal has nothing on the group. Signal publishes such requests, most recently in March 2026: 37 numbers, with these two dates available for 6.

With Threema they get almost the same, possibly with the converted phone number. In the first half of 2026, Threema handed over data on 2,026 accounts, more than in the whole of 2025 with 1,505.

With Telegram they have received internet address and phone number since September 2024. For Germany, that amounted in 2024 to 945 disclosures concerning 2,237 people, according to netzpolitik.org. The group with your messages sits on Telegram’s servers. By its own account, Telegram has never handed over content.

With WhatsApp they get account information. In the US, WhatsApp has also supplied, on court order and in real time, who someone is messaging. We found no figures for WhatsApp alone in Germany.

You were only being reminded about the wellies.

12A perfectly normal Tuesday

13What you can still change tonight

• WhatsApp: In the “Privacy checkup”, switch on “End-to-end encrypted backup” and choose a password you will not forget.
• WhatsApp: Reserve a username. Once the feature goes live, it is meant to hide your number from strangers.
• WhatsApp: Switch on “Protect IP address in calls”.
• Signal: In the advanced settings, switch on “Always relay calls”.
• iPhone: In the iCloud settings, switch on Advanced Data Protection. Apple then no longer holds the key to your backups.
• Signal: Under “Privacy”, “Phone number”, set it so that nobody can find you by your number.
• Telegram: Hold private conversations in a “Secret Chat”. Set peer-to-peer calls to “Never” under “Privacy”.

You do not choose the nursery group’s messenger on your own, though. Since 11 August 2026, Saxony has advised teachers against using WhatsApp for work or belonging to private parents’ groups. Baden-Württemberg gives teachers Threema free of charge; parents pay €4.99.

Whether WhatsApp will soon show adverts from other companies in Germany is still open. In March 2026, Meta announced the EU launch for “the coming weeks”. In our test in October, they had not appeared yet.