Huge portions of those people do not condemn the violence and think it is justified. There have been surveys after similar incidents(the London bombings, the Danish cartoonists, etc.) and even within British Muslims the numbers are quite frightening. Pretty big numbers do follow the idea "if you insult my prophet, you deserve what's coming to you"...
And just so I don't throw empty statements here are the Pew Research numbers:
2007 Pew Research:
poll in response to a question on whether suicide bombing and other forms of violence against civilian targets to defend Islam could be justified:
- 64% of Muslims in France believed it could never be justified, 19% believed it could be justified rarely, 10% sometimes, and 6% thought it could be justified often.
- 70% of Muslims in Britain believed it could never be justified, 9% believed it could be justified rarely, 12% sometimes, and 3% thought it could be justified often.
- 83% of Muslims in Germany believed it could never be justified, 6% believed it could be justified rarely, 6% sometimes, and 1% thought it could be justified often.
- 69% of Muslims in Spain believed it could never be justified, 9% believed it could be justified rarely, 10 % sometimes, and 6% thought it could be justified often.
- 45% of Muslims in Egypt believed it could never be justified, 25% believed it could be justified rarely, 20% sometimes, and 8% thought it could be justified often.
- 61% of Muslims in Turkey believed it could never be justified, 9% believed it could be justified rarely, 14% sometimes, and 3% thought it could be justified often.
- 43% of Muslims in Jordan believed it could never be justified, 28% believed it could be justified rarely, 24% sometimes, and 5% thought it could be justified often.
- 28% of Muslims in Nigeria believed it could never be justified, 23% believed it could be justified rarely, 38% sometimes, and 8% thought it could be justified often.
- 69% of Muslims in Pakistan believed it could never be justified, 8% believed it could be justified rarely, 7% sometimes, and 7% thought it could be justified often.
- 71% of Muslims in Indonesia believed it could never be justified, 18% believed it could be justified rarely, 8% sometimes, and 2% thought it could be justified often.
Here's the link:
https://pewresearch.org/files/old-assets/pdf/muslim-americans.pdf#page=97
Here's a newer one from 2013 with similar numbers. It says that estimated 72% of the Muslims worldwide think violence against civilians is never justified. That makes 28% of 1.6 billion followers that believe that at least in some cases violence against civilians is justified to defend the faith. If you just think about it you will realize just how scary that is.
https://www.pewforum.org/2013/04/30/the-worlds-muslims-religion-politics-society-exec/
In 2007 NOP Survey found that 25% of British Muslims thought that the 7/7 terrorist bombings in London were justified, because of the involvement of the UK in the Iraq and Afghanistan wars.
Link:
https://www.cbsnews.com/news/many-british-muslims-put-islam-first/