The punishment within the Quran for adulterers is lashes. Stoning is not mentioned anywhere in the Quran. Physical harm upon another for no reason is of course insane. But adultery is a crime and the lashings are just. If you don't do it you don't have to worry about it!
Second you have to have 4 witnesses to confirm it actually happened and actually saw it happen otherwise the person accusing will be lashed him/herself
Second you have to have 4 witnesses to confirm it actually happened and actually saw it happen otherwise the person accusing will be lashed him/herself