The problem isn't conversion, it is the supremacist ideology.
There are nations that hold to Islamic law, a political system, not a religion. There are practioners who want everyone under that political system. At least bowing to the supremacy of that system and respecting their laws of blasphemy, never mind that First Amendment in OUR country.
I don't consider all muslims a threat. However this is not a generational fad that will pass with time. It flares up around the world and lasts for centuries. More must be done from within mosques to end this dream of world domination. The West does not have theocracies although it has a dominant faith. While there are some laws inspired by biblical texts (including the 10 Commandments), many have been dropped by legislatures (including many blue laws on Sundays and laws against adultry...).
Islamic societies codify one set of rights for muslims and another for non-muslims (Jews and Christians being lesser under the law and atheists, Buddhists, and Hindus below that).
Again, vandalism and vigilantism is not the answer. It never is. But there is no analogy between Christians and muslims.
Again...I can't make this any plainer than I already have. I am not comparing the validity of religion's. I was raised Catholic, I married a christian, I've hung out with muslims, lost my virginity to a Presbyterian (she was quite a good amabassador for her faith).
I don't care who or what a person worships. You can worship an oil can for all I care. All I ask is that you treat me and my family with courtesy and respect. The muslims I know have done that so I reciprocate. As a result, we all get along nicely. I don't thorw pig parts at them, they don't try to kill me. It works out really well for us...