Bruce Schneier in a recent blog post,

If you’re a WhatsApp user, pay attention to the changes in the privacy policy that you’re being forced to agree with.

tl;dr - Facebook is going to take your data and use it however they want.

Schneier gives links on his blog. I’ve said it before and I’ll say it here. Facebook is a criminal enterprise. I do not recommend using anything owned by them. I haven’t regretted my decision to delete WhatsApp.