People often fiddle around their WhatsApp profile pics. And mostly this profile pic express the feelings/emotions of the user and his/her current status in Life.
WhatsApp application allows to "save" profile picture of a contact using "share" icon and then choosing option of "Save to Gallery".
Firstly, I am not sure if this is legally/morally appropriate as this sound like violates a privacy of the contact because this feature of WhatsApp is allowing a profile pic to "download" on other person's phone, without his/her knowledge.
Secondly, Is there a way to know who all downloaded or Saved the WhatsApp profile picture?