WhatsApp Public Groups Can Leave User Data Vulnerable To Scraping

An anonymous reader writes: WhatsApp differentiates itself from parent company Facebook by touting its end-to-end encryption. "Some of your most personal moments are shared with WhatsApp," the company writes on its website, so "your messages, photos, videos, voice messages, documents, and calls are secured from falling into the wrong hands." But WhatsApp members may not be aware that when using the app's Group Chat feature, their data can be harvested by anyone in the group. What is worse, their mobile numbers can be used to identify and target them.

WhatsApp groups are designed to enable groups of up to 256 people to join a shared chat without having to go through a central administrator. Group originators can add contacts from their phones or create links enabling anyone to opt-in. These groups, which can be found through web searches, discuss topics as diverse as agriculture, politics, pornography, sports, and technology. Not all groups have links, but in those that do, anyone who finds the link can join the group. While all new joining members are announced to the group, they are not required to provide a name or otherwise identify themselves. This design could leave inattentive members open to targeting, as a new report from European researchers shows. WhatsApp is used by more than 1.2 billion users worldwide.

Re:

[Zaelath]

That's what you get when valuations are based on user growth...

The android reviews are hilarious, there's about 2% that look genuine in the 5 star reviews, then stuff like:

Nithin Samuel
February 3, 2018
Worst update.
(That's what gets 5 stars from me, bad updates!)

Or these:

Lanchan gowda
March 19, 2018
Best apps for connecting with people

furkan sheikh
March 7, 2018
Connect with all dear one good app...

Prabhakaran p
February 11, 2018
Use full to connecting people

G Anu
March 18, 2018
Connecting people
(I guess this one di

Re:

[hjf]

You have no idea how big WhatsApp is in Latin America and Europe

Re:

[hjf]

People don't ask for your phone number here. They ask for your WhatsApp.
And all telcos have "unlimited Whatsapp"

What?

[Obfuscant]

"But WhatsApp members may not be aware that when using the app's Group Chat feature, their data can be harvested by anyone in the group."

So, if you share your data with a group, anyone in the group can access your data. D'oh. What am I missing here?

"What is worse, their mobile numbers can be used to identify and target them."

So, if someone has your mobile number, they can use it to identify you and target you. D'oh again. Is this really surprising?

Re:

[rioki]

Exactly my thoughts...

Like the people that share stuff publicity online are amazed that people unknown to them can access it...

Re:

[hjf]

Users in WhatsApp are identified by their phone number. If you join a public group (either because someone added you, or you clicked a link), the members that don't have you as a contact see your phone number.

You can't opt out of being added to a group. If someone adds you, that's it. You can remove yourself from the group, but there is no confirmation to add you.

Re:

[xvan]

You can't opt out of somebody else sharing your number. This is a no argument.

Re:

[hjf]

Are you dumb?

Re:

[hankwang]

Whatsapp will by default display your full name and phone number to group members that you don't know, in a group that you didn't necessarily ask to join. You can replace your full name by a nickname, but you have to be aware of the need. When you install Whatsapp, "this name will be visible to your Whatsapp contacts" does not make it obvious that "Whatsapp contacts" include those group members.

Re:

[xvan]

The real issue, not explained here. Is that whatsapp chats are encrypted end to end. If we are to believe Facebook, they can't read you conversations (unless their explicitly target them).
On Chat groups the conversations are logged on Whatsapp servers.

Woke yet?

[ElitistWhiner]

Any questions why?

Facebook owned?