Islam? Do you mean Mecca?
Ok let me tell you what I believe is the worst rule of all. This is serious, by the way.
Women have no rights there, so if they are accused of anything in courts, they are almost always found guilty. For example, if a woman is raped, she has to have 3 other women watching to be able to have the man arrested. If there is a man there, then the rapist will be jailed. But, if the woman is raped without anyone around, as most rapes happen, she can't turn him in.
But that isn't even the rule. Because the women are almost always found guilty, if a woman is accused of adultery, they bury her waist-deep in sand, and then have the village stone her to death. First her father throws a stone at her, then her husband throws a stone at her, then her sons in order of oldest to youngest throw stones at her, and then the entire village joins in and kills her.
Christianity has worse rules, if you even bothered to read your own holy book, you'd notice that there is a long list of people who should be killed and sent to eternal torture, everything from everyone who is not a Catholic, to any woman who speaks without a mans permission, to any kid who has ever disagreed from their parents. The simplest of things warrant being murdered and tortured in Christian mythology.
