[Later: curing "Islamophobia".]
Why am I so concerned about Islam?  What is it about that religion, more than any other of the fairy tales of the "world's great religions" that gets me riled?  Am I not being unfair?  Isn't it true that all religions are equal, to each  their own way to God, to Allah?
And if the Koran is a problem, well isn't the Bible equally problematic?  Isn't it also violent?
No, not really.
Islam is "unique" in that no other religion has a mandate of warfare against unbelievers.
It's true that the Bible is as violent as the Koran. But the vast majority of Christians today follow the New Testament, not the Old.  Even in the Old Testament, the violence is descriptive of battles happening at the time: it is descriptive, not prescriptive. By contrast, the Koran is prescriptive and eternal: it says that warfare against unbelievers must be carried out at all places and all times. Further, the word  "Bible" means "library",  a collection of books written by man, whereas the Koranis the "uncreated" and "inerrant" word of God.
Islam requires warfare against unbelivers.  In its doctrine (the Koran, the Hadith, the Sirah), in its theology (the Sunnah, the teachings of Imams in mosques throughout the world), in its legal systems (Umdat al-Salik), Islam teaches warfare against unbelievers. Other religions do not.
In short: Islam has a doctrine, theology and legal system that mandates warfare against unbelievers. Other religions don't.  That makes Islam unique in that regard.
In short, Islam is, by its own doctrines:
  • Supremacist
  • Sectarian
  • Homophobic
  • Misogynist
  • Against the freedom of speech
  • Against the freedom of conscience
  • Against the rights of minorities and non-Muslims.
Islam is free to be as sectarian, as homophobic, as misogynist, as anti freedom of speech as it wishes.  Freedom of religion!
It's the supremacist bit that does it for me. Islam believes, really really believes, that it must convert all unbelievers (kuffars).  Either that, or the kuffars pay a jizya tax, or they are killed.  Only three choices.
I write as an atheist, not as a Christian. I believe all religions are fairy tales.  But most are benign.  Only Islam --  only Islam -- makes its cause to convert the rest of humanity to Islam, by dawa (proseletizing) or by jihad (fighting: either violent or stealth).

The case against Islam. Feb 7, 2006

I came across this summary, which fact-checks (numbers refer to surahs in the Koran):

Muhammad was a self-serving (33:50-53), intolerant (5:51), polygamist (4:3) warlord (8:1, 33:27). He recruited warriors by promising them spoils of war (8:69, 48:19-20) and big-breasted virgins (78:33) in a gold-filled paradise (81:31). Muhammad used these fighters to spread his religion with the sword (9:5, 9:29), enrich himself thought conquest (8:1, 8:41) and gain access to the women who were captured or made widows by his advancing army (33:50, 70:30). Others joined to avoid the humiliating “infidel tax” (9:29), death, mutilation or expulsion (5:33). While writing the Quran, Muhammad worked in many personal, tailor-made advantages for himself (33:37-38, 33:50-53). The Quran allowed Muhammad to dominate his wives (33:30-34) even after his own death (33:53). He warned his wives that they will burn in hell if they reveal his secrets (66:3-5, 66:10). Muhammad used this “holy book” to slander the Jews (2:96, 5:13, 5:82) as well as his personal (111:1-5) and political enemies (9:13-14). The Quran contains scientific (13:3, 67:5, 86:7), mathematical (4:11-12) and historical (18:83-97) errors in addition to sexist (4:34, 2:223, 2:228, 23:6) and barbaric (5:38) teachings that have no place in the world today.