After 9/11 literally thousands of hate crimes have been done against Muslims and even Sikhs who are confused with Muslims (Sikh temple shooting in Wisconsin in 2012) Islam is the most discriminated against religion in America. Sadly there are many ignorant people who don't even know anything about any religion.
Anti-anything is a problem in American. The problem is, that it's done so quietly, that not many people find out about it. Because the US is currently oversees either protecting or killing these people to keep us safe, Americans sometimes feel like they can't trust people of the Muslim group. Which sometimes unfortunately brings violence.
Any racial profiling and violence against a different religion or a different group of people are wrong. It does not make you look good as a country and does not help you progress on a immigrant level. It will always be a issue and one that divides people and enhances more violence.
I think anti-Muslim antics in America are probably confined to more subtle methods than violence. They are probably the targets of hate speech, overt or covert discrimination, but I doubt it always escalates to violence. Especially relative to areas in the Middle-east where this violence is much worse and much more often.
I do not think that, in general, anit-Muslim violence is a problem in America. I am sure that it does happen, but most people who feel negative about Muslims just talk about how horrible Muslims are to them. Most people who dislike Muslims never do anything about it but run their mouth.
I don't think anti-Muslim violence is too common in America right now, but I think it wouldn't take much for it to become a problem. Muslim people in America seem to keep a low profile. They stay within their own communities and work hard. I think many of them feel shame over the Muslim radicals who choose to live by violence.