For nearly a decade, I've been gathering and studying details from breaches. In the beginning, there wasn't much, but over the years, more and more has emerged in the public record. There's enough data now that it's time to start talking about what we can learn from the failures of others. This will follow up on my RSAC 2026 talk, which focused more on making the argument for breach transparency. This talk will focus almost exclusively on the specifics I've learned from a decade of studying breaches, which the RSAC talk only shared a sample of.