In memory. If the police shows up and they disconnect my server to sieze it, for example, the photos are lost to them.
And the Hetzner employee would need to specifically target me, because I doubt they would implement a dragnet that pierces through the bespoke random process on my bare metal server to scan the photos in memory.
That is a lot more secure than „Google scans all pictures routinely and fully automatically sends the police to your door, and you have no recourse if they are wrong“ that the EFF article discussed.
And the Hetzner employee would need to specifically target me, because I doubt they would implement a dragnet that pierces through the bespoke random process on my bare metal server to scan the photos in memory.
That is a lot more secure than „Google scans all pictures routinely and fully automatically sends the police to your door, and you have no recourse if they are wrong“ that the EFF article discussed.