retain control

Notably, in Quarks, every user operation and information exchange that takes part on a channel is carried out via the ledger's so-called smart contract. In practice, this means that no-one outside of a channel should be able to send or read messages on it. In addition, all messages on the channels cannot be altered or edited, yet they can be audited, meaning that users should be able to derive information about when they were created, sent, delivered, and so on.

Ah, yes. I definitely want anyone in the world to figure out who I'm communicating with by checking the timestamps of when various messages were delivered. Much like how the "anonymous" Bitcoin could be pretty easily de-anonymized just by checking where various bitcoins go and inferring who those wallets likely belonged to.