I believe their point was that even encrypted messages convey data. So if you have a record of all the encrypted messages, you can still tell who was talking, when they were talking, and approximately how much they said, even if you can’t read the messages.
If you wait until someone is gone and then loudly raid their house, you don’t need to read their messages to guess the content of what they send to people as soon as they find out. Now you know who else you want to target, despite not being able to read a single message.
This type of metadata analysis is able to reveal a lot about what’s being communicated. It’s why private communication should be ephemeral, so that only what’s directly intercepted can be scrutinized.
Yes, but that’s the case regardless. My message going through has always depended on someone else’s cell towers, all the random routers and switches in between, and the other person’s device.
My server likely has worse uptime, and if I’m hosting from home it probably has more hops to transit through it.