Here are things which people think that they belong to islam but actually are unislamic.
Soon after Muhammad’s death, thousands of hadiths (words attributed to Muhammad) were fabricated and two centuries later collected, and centuries later compiled and written in the so-called “authentic” hadith books:
to support the teaching of a particular sect against another (such as, what nullifies ablution; which sea food is prohibited);
to flatter or justify the authority and practice of a particular king against dissidents (such as, Mahdy and Dajjal);
to promote the interest of a particular tribe or family (such as, favoring the Quraysh tribe or Muhammad’s family);
to justify sexual abuse and misogyny (such as, Aisha’s age; barring women from leading Sala prayers);
to justify violence, oppression and tyranny (such as, torturing members of Urayna and Uqayla tribes; massacring the Jewish population in Medina; assassinating a female poet for her critical poems);
to exhort more rituals and righteousness (such as, nawafil prayers);
to validate superstitions (such as, magic; worshiping the black stone near the Kaba);
to prohibit certain things and actions (such as, prohibiting drawing animal and human figures; playing musical instruments; chess);
to import Jewish and Christian beliefs and practices (such as, death by stoning; circumcision; head scarf; hermitism; rosary);
to resurrect pre-Islamic beliefs and practices common among Meccans (such as, intercession; slavery; tribalism; misogyny);
to please crowds with stories (such as the story of Miraj (ascension to heaven) and bargaining for prayers);
to idolize Muhammad and claim his superiority to other messengers (such as, numerous miracles, including splitting the moon);
to defend hadith fabrications against monotheists (such as, condemning those who find the Quran alone sufficient); and even
to advertise products of a particular farm (such as, the benefits of dates grown in a town called Ajwa).
http://19.org/blog/manifesto-for-islamic-reform/