If a community has a special interest in the movies, songs, news and culture of a particular foreign culture portrayed in its media, it may have a strong impact on that community.
You are absolutely right about the impact of foreign media dominating a given culture . The media are a source of input enhancement and they provide learners with a useful source by which the can improve their learning. They also cater to authentic material that are much needed in L2 classrooms.
It is a given that foreign media and their foreign language would naturally influence the culture and language of their host nations. However, this influence is predicated on prolonged exposure and assimilation.
A culture values affect on the other culture values depending on how much those countries culture are similar or different. Countries, for example, including Pakistan, Nepal, and Bangladesh can be influenced by Indian culture or media faster than Arabic countries. So, similarity or difference on cultural values is the Key response.
Languages and cultures are rapidly either disappearing or being hybridized, particularly by the hegemonic languages (English, Spanish, French). In some cases as a result of state policy, certain local languages come to dominate other languages or dialects within the country as de facto national languages (reinforced through popular media). Without question, however, English has become a virtual worldwide lingua franca, and the Internet is playing a major role in disseminating its use. That said, other major languages, including Chinese, HIndi, Arabic, German, Italian, Swahili, Russian, and others will continue to survive and prosper long into the future. But American and British English, I believe, is at the forefront, again largely because of the media, of changing not only language use but cultural values and ways of seeing.