Attacks Rise on Muslims In Scotland

There has been a significant rise in attacks on Muslims in Scotland since the crashing of a car into the Glasgow Airport by some terrorists. It is apparent some people in Scotland assume that if someone from a group commits a crime, then all members of the group are equally guilty. It is estimated attacks on Muslims in Scotland have risen by about one-third since the bombing attempt.

Why is it that no one ever assumes if a white skinned Christian does something wrong, all white skinned Christians are equally guilty?