Youtube and Facebook are the best ones I know of. I know they're not private and I know you can get banned mid-stream via user-report but they have a lot of problems taking down suicide streams.
Some have been on for weeks some days.
Thank you very muchI believe Katelyn Nicole Davis used LiveMe to broadcast her hanging suicide four years ago (along with hours of other preserved live streamed records of the last month of her life). The replay has remained online through various sites ever since.