isis claims the horrifying list of punishments is a ` warning ' to disbelievers .
it pertains to syrian province aleppo and claims to be based on sharia law .
penalty for insulting god , his messenger or the religion of islam is death .
thieves ' hands are chopped off , adulterers are publicly killed by stoning .
list says committing ` calumny ' - or slander - is punishable by 80 lashes .
islamic state 's brutal executions are common on its social media channels .