I can only speak of WhatsApp from my own experience, and re the Facebook connection, I discovered an option just recently in "Settings/Account" to choose not to have my WhatsApp details shared with Facebook.
A no-brainer for me as I don't use Facebook. But, the option was there, and once you tick off your choice, it disappears.
If you are an existing user, you can choose not to have your WhatsApp account information shared with Facebook to improve your Facebook ads and products experiences. Existing users who accept our updated Terms and Privacy Policy will have an additional 30 days to make this choice by going to Settings > Account.
https://www.whatsapp.com/legal/
I'm not a WhatsApp fan boy, although I do think it's a fantastic app, and unlike a lot of others, still doesn't hit you with ads at every turn. In fact so far it hasn't hit me with any ads at all.
Re the privacy side, I'm becoming a lot more of a realist about how much privacy we actually have in this world and in the real one.
For instance, how many councils quite legally sell your "private" information to commercial interests? I know mine does, because I questioned a spam caller as to how they got my number, and she admitted their company buys them from local councils.
A recent example ...
Local councils sell on YOUR details for £64,000:
As long as WhatsApp continues to encrypt all exchanges of information between users, and I believe they don't store this type of info on their servers (as per their privacy policy), then I care less what they do with my smart phone number, which they must have presumably for me to use the service.
Very little is really private these days to the point where you'd have to retire from the world to achieve real privacy.
This is just something you have to either accept, or simply not use the various services. In my case, with my family living in another country, WhatsApp and Skype are well worth any negative privacy issues. No big deal is the way I look at it now.
By the way, this isn't a contra-argument to my good friend Logins post above, just my take on what one has to accept to reap the very good benefits of very good free software.
Now Facebook is something else, but I no longer use it so won't go there. ![:)]()