Gun control has been a current events issue in the United States for many years. Recently, it became more important to people in the wake of the school shooting in Newtown, CT in December of 2012.
From time to time, some people in the US want to have more limitations on guns. This is a major issue to some people because the amount of gun violence in the United States is horribly high compared to other rich countries. When there are mass shootings like the one in Connecticut, the demands for gun control tend to get louder because such massacres are often carried out using things like semi-automatic weapons with large clips of ammunition, both of which gun control advocates would like to ban.
However, such calls are always controversial and are usually unsuccessful. The reason for this is that many Americans believe that they have a constitutional right to carry more or less whatever sort of gun and ammunition they want. They feel that attempts at gun control are a thinly disguised plot to take away their gun rights. They believe that the government will then further abuse their rights because they will not have any guns to use to defend themselves.
It is for these reasons that gun control is an issue in current events.