I think I know that media is a plural word.
So then which one is correct,
"All the media is"
"All the media are"?
When you search Google, both seem to appear at the same frequency...
Actually, when I google for these phrases, I'm seeing this:
The Corpus of Contemporary American English paints a similar picture, though the sample size is rather small (1 vs 3 cites). You get more results if you leave out the "all" (445 vs 602). These numbers also include a few cites of the form "the quality of the media is..." or "many in the media are...", which are obviously not relevant here, but the overall trend is still rather clear.
The British National Corpus, on the other hand, favors the plural form. There are fewer results overall, so I took my time to check every single one for relevance, and here's the overview:
So the Americans prefer the singular form, while the British prefer the plural. This should come as no surprise knowing that the British like to treat other collective nouns such as staff, Microsoft or Metallica as plural, too, while Americans prefer the singular. See these answers to related questions:
Media can be treated either as singular or plural. When used in the singular, it is often treated as a collective noun.
Here is what the OED online says:
Merriam-Webster's Dictionary of English Usage (see page 630) also notes the use of media in the singular. It gives examples of it being used as a singular countable noun as well.
In short, the usage of media as a singular noun is well-documented.
Language and usage evolve, but I’m sufficiently reactionary to regard “media” as plural, regardless of contemporary examples. In regard to the Fourth Estate, “media” to me signifies the print medium, the broadcast medium, et. al.
Of course, this comes from one who occasionally uses “Yr. obt. svt.” as the complimentary closing on my correspondence...
I think treating "the media" as a singular (when speaking of the Fourth Estate) has become so overwhelmingly common now that it has to be treated as acceptable, though it bothers me and I would always personally prefer the plural usage.
If the sentence were about data storage media or some such, I think the plural would be more strongly called for.