So, what should we use?

A libre software license.

Which lines of its libre software source code are malicious?

My friends knew I was using it. I said why with very simple words, focused on freedom and abuse over side effects, privacy and security, and they joined. I guess having friends who actually respect you helps a lot.

Thanks, updated!

• SimpleX is libre software and the most decentralised voice chat here.
• Briar is libre and the most decentralised but is missing voice chat.
• XMPP and Matrix are libre software and federated/decentralised. XMPP servers use far less resources, so creates more decentralisation than Matrix in practice.
• Signal is libre and more popular but centralised, acceptable.
• Avoid Threema's app which requires a service as a software substitute.

So, they already did it. This will never bring our data back.

GDPR has never stoped them breaking laws. Fines are the cost of doing business. When we give anti-libre software our data, it's game over.

I would invest more into stopping 'friends' encourging me to get abused than micro-optimising the malware infecting me. Not saying don't break it down into steps.