The many opportunities denied women under Islamic law, from giving equal testimony in court to having the right to exclude other wives from their marital bed, is very clear proof that women are of lesser value then men in Islam. Muslim women are not even free to marry outside the faith without being killed by their own families.
Islamic law also specifies that when a woman is murdered by a man, her family is owed only half as much "blood money" (diya) as they would be if she had been a man. (The life of a non-Muslim is generally assessed at one-third).
Although a man retains custody of his children in the event of his wife's death, a non-Muslim woman will automatically lose custody of her children in the event of her husband's death unless she converts to Islam or marries a male relative of within his family. Even the rights of Muslim mothers are subordinate to her husband's family.
Contemporary Muslims like to counter that Arabs treated women as camels prior to Muhammad. This is somewhat questionable, given that Muhammad's first wife was a wealthy woman who owned property and ran a successful business prior to ever meeting him. She was even his boss... (although we're sure that changed after the marriage). Still, it is somewhat telling that Islam's treatment of women can only be defended by contrasting it to an extremely primitive environment in which women were supposedly non-entities.
Homa Darabi was a talented physician who took her own life by setting herself on fire in public protest of the oppression of women in Islamic Iran. She did this after a 16-year-old girl was shot to death for wearing lipstick. In the book, Why We Left Islam, her sister includes a direct quote from one of the country's leading clerics:
Muhammad captured women in war and treated them as a tradable commodity. The immutable, ever-relevant Qur'an explicitly permits women to be kept as sex slaves. These are hardly things in which Muslims can take pride.