How come people nowadays say that the punishment for adultery is stoning to death?

I have read enough stories and what I found was that during Prophet Muhammad's time the punishment for adultery was a 100 lashes, nothing more,nothing less. If Prophet Muhammad did not support stoning to death, then who are these Imams? Which barbaric Imam invented these laws to suppress and murder men and women and call it the law of Allah? I hope they go to hell for murdering, it's one of the major sins in Islam.