When referring to the overall news media, can I use the capitalized word "Media"?
Overall news media is media. Single media sources are actually called mediums.
It's from Latin. Singular - Medium. Plural - Media. Depends on the context, but i'm guessing overall is everything overall. In that case, why not?
Actually, why would you do that? It's one thing to emphasize with Capitalizing, but a properly structured and worded sentence can go miles further than any attempt at poor emphasis indication.
I'd rather you not, but you can. Valid, but not... nice?