I am SO relieved that I was NEVER a LostProphets fan.
I think I liked a grand total of one of their songs.
Unfortunately - I know someone who was in one of their music videos..
I liked a handful of their songs, mostly from Start Something. I have a good friend who invited me to her place in about 2010 or 11 and we got rotten drunk and played each other's favourite bands to each other. She gushed over Lostprophets. She was quite heartbroken when the dude pleaded guilty.
In an effort to keep this thread super light, a few more names that come to mind, but no-one else has mentioned:
Euronymous and Vikernes of Mayhem. Euronymous drove his friend and bandmate, Dead, to suicide, then, upon discovering the body, bought a throwaway camera, took photos of the body before calling the police, and used the picture as the cover of the band's first album. Vikernes then went on to stab Euronymous to death. Both men were also involved in burning down churches throughout Norway.
Charlie Manson has released music while in prison. I listened to some of the tracks from his first album on youtube out of curiosity, and I thought they were surprisingly good.