Well by that raionale, would you consider the KKK to be Christian? After all, they espouse that their beliefs are based on biblical theology.
Yes, actually. At least, it is in the core of their beliefs, twisted and perverted as it is. They don't represent Christianity accurately, but they are christian, technically. They wouldn't be the first such example. King Charlemagne slaughtered hundreds of pagans who wouldn't convert at Verden in 782ce. Sound familiar?
It must be noted however, the bulk of any atrocities in xtianity's name were committed hundreds of years ago, and at that, were not at all in character with the tenants of the religion; Jesus did not advocate violence or war; whereas the Koran has dozens of bloodthirsty suras, further which don't appear to be in a constrained historical context in the manner which old testament atrocities are presented, but an open-ended command to be followed herewith.
To their credit as ethical human beings, I think moderate muslims keep the peace by selectively ignoring those distasteful parts of the Koran, even though they abrogate the earlier, more peaceful verses.