This makes me think of another potential privacy risk: if you paste a URL in WhatsApp, or click Android's share button and select WhatsApp, it doesn't add a spa

This makes me think of another potential privacy risk: if you paste a URL in WhatsApp, or click Android's share button and select WhatsApp, it doesn't add a space after the url. Most users are probably aware that they have to add a space, but if they forget, WhatsApp will probably send the first word of the rest of the message to the server. (Similarly if you paste a URL at the start of an already-written message, but maybe that's even more contrived.)