You can think what you want about Facebook, but they operate a massive amount of compute and storage unites. And it seems, they have some scientist investigating interesting phenomenon like this. To be honest, it is not primary backup related but in the second instance it is restore related 😀
They found out, CPU can perform computations incorrectly. So it comes to silent data corruption by CPU. According to their observations these failures are reproducible and not transient. When you think about data-reduction technologies like compression this really can cause problems. As the following article describes, these corruptions occur at scale. Interesting is also how they test their hardware.
Read more details here: