HN user
Well they don't need to store your whole message, once they have processed it and updated their profile database with whatever is of value to them they will most likely delete it. They should all happen within minutes if not seconds of you sending the message.
If you have WhatsApp and Facebook or Facebook Messenger installed on your phone then they are aware of each other and can exchange information freely.
They say the network communication is encrypted between end points but they don't say analysing is not being done prior to encryption on your end. What I mean is it is possible for the communication over the network to be encrypted between Bob and Alice but everything Bob writes to Alice could easily be used by WhatsApp/Facebook prior to being sent. They could even go as far as to encrypt it and just transmit your side of the conversation to their servers for later analysis.
WhatsApp isn't about putting ads into the app but for better data collection. That is why Facebook bought them. Facebook sells ads and targeting data and one of the best ways to analyse a persons life to better target them for ads is from their personal, non-public communication. You will talk about many more things in private conversation with friends and family than you will publicly on your Facebook profile.
A simple example is you are talking to a few friends on WhatsApp about booking a holiday somewhere, you talk about locations, dates, prices, etc. all in private, now Facebook can take all that data and using their massive Facebook tracking system start advertising offers for hotels in the places you are looking at going, shops you often mention that sell clothes for your holiday, travel insurance, etc, etc.
You don't need to stick ads IN the app to monetise it. In fact keeping it clean and ad free is the best thing to do as it keeps your users happy and using your app more which in turn leads to more and more data collection.
I think the $1 a year thing is a load of crap that is used to distract people away from the whole "if it is free you are the product" idea. If WhatsApp looks like it is not free because you have to pay $1 a year then psychologically you "trust" it more because it is something you pay for rather than something that is analysing every thing you ever say to build a better advertising profile. Also has anyone actually ever paid that $1? I don't know anyone who has, they always get some "promotion" that gives them another year free for being a loyal WhatsApp user.
Why is this at the top of HN? Didn't the 3rd edition come out ages ago? What exactly is new?
So what happens if a user defaults this via a user script to all pages on the NYT?
I do not believe you actually purchase the ability to print your Kindle purchases. I am not aware of a way without stripping the Kindle DRM.