Ask HN: Ads triggered by WhatsApp “end to end encrypted” messages?

If this is just in text—and I'm definitely not defending Meta here—could it also be that the ads you see have got us so figured out already? The topic you choose to talk about may be influenced or seeded by your environment (online/offline), and one thing leads to the other almost deterministically.

Here's an experiment: try rolling a die a few times or using a random number generator to pick one word or more from a list like the EFF wordlists [0], and then talk about that exclusively.

[0]: https://www.eff.org/deeplinks/2016/07/new-wordlists-random-p...

Or they can say, technically it wasn't a message before it was sent. The dictionary definition[1] even mentions "send".

[1] https://www.oxfordlearnersdictionaries.com/definition/englis...

I don't think there is any fault with the e2e encryption. Humans are very bad at seeing causality when there is none, or accidentally leaking their thoughts into the search box.

There could also be leaks with the clipboard, photo gallery or keyboard - all things that freemium apps love to scan in the background. The way real-time-bidding ad markets work, anyone that the data leaks to can influence ad ranking - doesn't have to be FB/Meta.

If you did a true blind study, I think you'd find no link.

For example, start with a list of 1000 products images and accompanying text. Select 2 at random each day. Flip a coin to decide which to send (keep the other as control). Cover the screen so the user can't see what they've sent/received. Then, a few days later ask the user to select which product they think they sent.

I'd bet that even after months of doing this, there will be no finding of a leak.

I think that 1 is the most plausible, however the original post is about "topics they never talk about", so assuming that WhatsApp is the only channel and they don't leak data in other ways (and there are many other ways to leak data), then 1 becomes unlikely.

3 is the most compatible. All the targeting can be done locally, so no end-to-end unencrypted message leaves the app. The app then sends your topics of interests to Meta.

4 again assuming WhatsApp is the only channel, then there is probably some malware somewhere, and it is unlikely that Meta accepts illegally collected data (they can do it legally, better, and with less potential trouble). There are however a few legitimate apps that can do the above. I am thinking about things like predictive keyboards, accessibility apps (screen readers, ...), backup apps (end-to-end encryption is about transmission, not storage), and the OS itself. I don't think Meta controls any of these, and I don't think they would buy data from them (Google and Apple are competitors after all).

So I would go for an accidental leak (case 1). For example, for the experiment to be meaningful, you shouldn't tell anyone about the test topic before you receive the ads. Or with the WhatsApp app hinting Meta about your topics of interest.