I recently saw this video: http://youtu.be/vnJBW49afzg
Let's put this in perspective - a group of self-professed 'Christians' shows up uninvited to a Muslim Arab Festival, where they are confrontational to the Muslims and insulting to the police, and they are carrying signs with slogans like "Repent - your party will burn in the lake of fire (01:14)," "Islam is a religion of Blood & Murder! (03:26)," "Be not believers in drunkards, whoremongers, idolaters, sodomites, fornicators (04:30)," "I am truth and the life - all others are thieves are robbers (04:30)."
No - this was not an act of random violence by a group of Muslim extremists who were targeting an innocent group of Christians; this was a deliberately-staged set of contentious actions by some very unbalanced people who claim to be Christians in order to provoke the very attack that transpired. These otherwise peaceful Arab-Americans were enjoying a day of celebration of their faith and heritage, and these so-called Christians showed up and behaved in an extremely insulting manner, shouting insults with a megaphone and slandering the Muslim faith - these 'Christians' might just as well have been Nazis based on their behavior. The police were 100% correct is telling these fools that they were the cause of the trouble.
Let's reverse things for a moment - let's say that you were a Christian at a peaceful church gathering when a group of atheists showed up to protest by using a megaphone to hurl insults at your religion and they carried signs that proclaimed that Jesus was a drunkard & whoremonger who was the illegitimate son of unwed slut, you would be more than a little offended. You might not personally react with physical violence, but if you had a few thousand Christians in one place when a publicly-outspoken group of atheists or Buddhists or Hindus or Muslims showed up and behaved as provocatively as these 'Christians' did, I can 100% guarantee that someone would eventually lose their cool and start throwing things.
This video is a perfect example of how Christians should NOT behave, and they are certainly not following Christ's example. This is not a question of exercising freedom of speech or freedom of religion - this is a question of exercising good judgment and Christ's love; this group of 'Christians' exhibited neither.
Self-professed 'Christians' like those in this video should be ashamed of themselves.