Extreme debris disks (EDDs) are rare systems with unusually large amounts of warm dust that are thought to stem from recent giant collisions between planetary embryos during the final phases of terrestrial planet growth. In my talk I will report on identification and characterization of a new sample of EDDs - all hosted by Sun-like stars - that triples the number of known objects of this type. While rocky planet formation models predict that the majority of giant collisions occur in the first 100 Myr, we found that the sample of EDDs is dominated by systems older than this age. This may indicate either that the era of giant impacts is longer than we think, or that some other mechanism(s) can also produce EDDs. Regarding this last point, I will outline some alternative models.