I like to approach an argument from a rational and logical manner. Data is a good place to start. The Washington Post published some statistics recently.
http://www.washingtonpost.com/wp-srv/special/nation/gun-homicides-ownership/table/
While the USA is at the top of the list when it comes to rates of gun ownership, it is by far not at the top of the list when you click and sort by rates of homicides by gun. In fact Jamaica with far fewer guns is much more murderous of a country. But no one seems to pick on Jamaica.
There's something more to this argument than simply more guns = more death. At least alone it is clearly not the root cause.
That being said, I am personally a big supporter of both personal freedoms, including rights such as gun ownership, but at the same time believe firmly in responsible ownership. That would include training and security checks.
So I believe in balance. Whether we have the correct balance in society now or not is certainly up for debate. Events like the horrible atrocity that occurred in Las Vegas certainly does make one pause and ponder this question so people's concern is understandable indeed.
Peace...