[ambivalence]

How do you mean "All your WhatsApp messages"? Isn't it by design that WhatsApp only ever stores undelivered messages? Once they reach the recipient, they're gone from the servers. This lets the infrastructure be really small compared to the number of users on the system.

[pilif]

Who knows what they do with the messages. They certainly weren't peer-to-peer encrypted, so for all we know, they were storing a copy "for later use".

Even if they weren't initially, they could have started storing them whenever they wanted without telling anybody or any other indication that they would.

Especially since the deal with Facebook, assume all messages to be kept around and linked with your profile.

[grahamel]

They back the messages up if you selected it in the settings (think it's opt in)

[jmathai]

That doesn't mean they don't back it up if you don't select it in the settings.

[bradbatt]

I don’t think it’s out of bounds at all to assume that these companies would keep as much data as possible—including your messages.