When Publishing Platforms Become the Weak Link

Good morning. This week brings a single story, but one worth your attention if you publish anything online or subscribe to those who do.

Substack—a platform many writers and podcasters have come to rely on for direct audience relationships—disclosed a breach affecting nearly 700,000 user records. The incident reminds us that when we choose centralized tools for distribution, we're also choosing their security posture, their incident response, and their transparency practices.

Below, we look at what happened, what was exposed, and what it means for anyone who treats email lists as critical infrastructure.