In Harm's Way

To the almost-immortal near-gods of the far future, life was eternally safe, and agonisingly boring. Nanobots rapidly repaired damage to their bodies, while a neural-net gave them instant access to the global database.

For a while, they distracted themselves by Pastiming, mentally jumping into someone in the past to experience their lives, but even that soon became dull.

Then someone discovered that if you stayed too long in the moment of someone's death, you never came back.

With that discovery, Pastiming was declared to be too unsafe... at which point, it immediately became the most popular activity in the world.