Sounds too outrageous to be true. Is there a more credible news source?

Good to know this mfer won’t kill any Ukrainians

How tf do you think those leaflets are delivered?

I hope Ukrainians do consult with North Korean POW’s on whether such leaflets would work on their comrades. Would be a waste of resources to deliver leaflets that just do not work

Graphene OS - best privacy and security, only for Google Pixel phones

Calyx OS - less secure but supports cheaper phones (Motorola) and eco-friendly phones (Fairphone)

Honorable mentions are LineageOS, /e/ OS, Replicant and iode OS, however their security is much worse than of Calyx/Graphene (no verified boot), so use at your own risk

Yes, they exist, but there is no reason to use them other than tinkering around. Also they have much worse security than Android or iOS. So if you need something private and open source there are a plenty of degoogled Android ROMs.