Obviously, I have no evidence for making such a claim. What I know is
1. Facebook's reputation with regards to privacy.
2. The fact that they paid 20 billion dollars to buy a product without a monetization model. (Which is 20 times more than they paid for Instagram by the way.)
3. Whatsapp's founder left the company after the acquisition due to privacy concerns.
Obviously, I have no evidence for making such a claim. What I know is
1. Facebook's reputation with regards to privacy.
2. The fact that they paid 20 billion dollars to buy a product without a monetization model. (Which is 20 times more than they paid for Instagram by the way.)
3. Whatsapp's founder left the company after the acquisition due to privacy concerns.
It's enough to be more than suspicious.