The Joint Declaration was agreed upon at an informal meeting of the European Chiefs of Police in London hosted by the National Crime Agency on 18 April.
Police Chiefs of all EU Member States and Schengen Associated Countries were invited, alongside Europol’s Executive Director.
Here is the declaration (pdf).
Facebook Messenger. After WhatsApp and WeChat, the third largest one in term of active monthly users apparently.
Thank you to translate the “Meta Messenger”, I was a bit confused as the only messenger of meta I was aware of is Whatsapp, whuch is e2e since like forever in software terms.