Muslims have often said that many extremist groups do not represent Muslims and that these people are not acting according to Islam.
Many people from the anti-Muslim brigade after throw ridicule at this idea suggesting that there cannot be fire without smoke and that we are apologists or burying our heads in the sand at best, or hiding Islamic teachings at worst.
Recently a "Boko Haram" was captured in Nigeria - this is a violent "pro Shariah" group that considered things such as teaching the water cycle as western propaganda.
Now, the interesting thing is that during interrogation, it was found that the commander could neither read the Qur'an, not did he know how to perform the Muslim prayer.
Boko Haram is active in Northern Nigeria and while it has a presence going back years, it was made notorious last year when it kidnapped many schoolgirls last year, in response to which the western world responded with a savage twitter campaign with the hashtag #bringbackourgirls that would have terrified the militants. Some high profile people taking part in that campaign probably never saw the irony between their messages and their actions.