It lacks trust and loyalty in social network. People can’t interact with each other personally and are from different areas. People can’t get to know each other well. In my opinion people only can communicate with each other online . Even though people can meet each other offline but it is dangerous to meet a strange net friend . Recent year there were so many criminal crimes due to people meeting net friend. A lot of girls were raped and killed when meeting their male net friend. How terrible it is.