"Abstract. I think there's a small but non-negligible probability that humans or their descendants will create infinitely many new universes in a laboratory. Under weak assumptions, this would entail the creation of infinitely many sentient organisms. Many of those organisms would be small and short-lived, and their lives in the wild would often involve far more pain than happiness. Given the seriousness of suffering, I conclude that creating infinitely many universes would be infinitely bad."
http://www.utilitarian-essays.com/lab-universes.html
"Abstract. I think there's a small but non-negligible probability that humans or their descendants will create infinitely many new universes in a laboratory. Under weak assumptions, this would entail the creation of infinitely many sentient organisms. Many of those organisms would be small and short-lived, and their lives in the wild would often involve far more pain than happiness. Given the seriousness of suffering, I conclude that creating infinitely many universes would be infinitely bad."