One of the best parts of living in the United States is our multicultural society. However, some citizens live in less culturally varied areas and don't come into contact with cultures different from their own. These people might have no other option than to turn to the media containing these cultures to learn more about them.
Historically, cultures have tended to remain isolated from one another through various physical boundaries. With the boom of technology ever dissolving these physical boundaries, our planet shrinks and cultures enmesh. The Internet, free-to-air satellite TV, shortwave radio -- all are such "channels" bridging the gap between regions on our planet. To what degree people engage in these available modes of communication determines just how much cultures are affected. Each culture has its own presuppositions -- its own perception of the world. Foreign channels will inevitably expose one to differing points-of-view. This allows one to see the world 'through the eyes of another'. It brings forth an increase in empathy and understanding.
America is a multicultural nation. It is not a Christian country or a Anglo-Saxon protestant country. Foreign language channels offer newly arrived people to have a valuable source of information while they work to assimilate themselves into America. Plus, it broadens the cultural horizons of other people who may not normally get to experience other cultures.
My reasoning for saying no is simple. Our culture is a potluck of various foreign cultures so foreign channels could not effect our culture. They are already a part of it. The only difference is the change of technology and now people can access these channels easier than they could even twenty years ago.