The point of naming something a sin is a warning not to use it overly, in other words, everything in moderation. If you are a Christian, then you have been taught that it is human nature to sin. As we accept this, we become aware, making ourselves conscious, and giving us choice. Only when we obsess, or overuse do we become sinful. That's why it's best to use moderately, and seek spirituality through Christ, and therefore filling emptiness inside you with Him, and not sin.
http://deadlysins.com/sins/index.htm