WhatsApp embeds google analytics into your client, which means that it does tag all your messages while you are viewing them (and also tags them with each open/

WhatsApp embeds google analytics into your client, which means that it does tag all your messages while you are viewing them (and also tags them with each open/close of the conversation). If you don't know this already, use App Warden to remove spyware handlers on Android and use RethinkDNS to block their ad domains.