Security researchers can and probably have tested for this and found no clear, verifiable evidence, otherwise we would have known.
Facebook snooped on users’ Snapchat traffic in secret project, documents reveal
By paying people $20 / month in exchange for installing a VPN that will snoop on your data so they can market research their competitors.
It is unacceptable, but it wasn’t in secret from the users. They agreed to get paid in exchange for the usage data of competitor apps.
So it’s a completely different situation to any “secretly spying” claim. The users had to go out of their way to get it setup.
it wasn’t in secret
Did I misread something? It even says in the title of the linked article, that it was a “secret project”.
Yes, it was secret in the sense they didn’t want their competitors knowing about it.
It wasn’t secret to people who were invited and signed up for the program.
Yes. Just another malicious thing facebook does. Surely, they are totally trustworthy in all other regards. /s