I have several friends of the Sikh religion. To a person they are peaceful, god fearing people and no one deserves the tragedy they suffered this weekend.
I know that sometimes they are persecuted because of their beliefs but if people knew the truth, I believe that peoples opinions would change.
I'm no expert, but in their religion they believe that you are perfect when you are born and you don't change things that are perfect, thus the men never cut their hair and wear a turban to hold it in place. This is often an object of derision by those that don't understand.
Sikh's people are in many countries in asia where the Brits brought them as contract labor, Then the stayed. I met many and had a few friendships. The are a proud people and I too am saddened by this too.