I have slept with them in before once because I was half asleep already when I remembered about them....I woke up as normal in the morning and took them out. I had no discomfort, and no orgasms! I think I read that you're not really supposed to wear them for more than 8 hours at a time, so it's ok to sleep with them in as long as you don't sleep longer than that, and put them in just before bed and take them out as soon as you get up!
I wouldnt recommend sleeping with them in. May do ur inside damage .when your awake you notice warning signs that your body has tired or enough of them and this not case when your sleeping
ive only just got my first pair today im so nervous to use them! x
After reading these comments every time now i see a woman walking along smiling i will be assuming that she has something nice on the "inside" ! 
Your fine to sleep with them in. I have the hematite magnetic set and regularly wear them for 8-12, hours at a time. Have fun
not somthing i would do however if its comfortable i dont see a problem x
I have had the same little experience as PurringPussy and LibraLover, having fallen asleep while wearing them. Nothing very interesting happened.
(That reminds me I am after some new ones, the pair I have is obviously a way too large/light for me...)
ive worn a butt plug to sleep, takes a bit longer to fall asleep and when you wake up its a nice ooh surprise lol
I've accidently slept with them in with no weird side effects.
I would be scared to I think! Just in case anything happened.
I think it does depend on what ones you have too though- some might work/not work better as others
Working out with them in would be a super workout too!!