media

The singular media and its plural medias seem to have originated in the field of advertising over 70 years ago; they are still so used without stigma in that specialized field. In most other applications media is used as a plural of medium. The popularity of the word in references to the agencies of mass communication is leading to the formation of a mass noun, construed as a singular.

• • there's no basis for it. You know, the news media gets on to something
  • —Edwin Meese 3d
• • the media is less interested in the party's policies
  • —James Lewis,  Guardian Weekly

This use is not as well established as the mass-noun use of data and is likely to incur criticism especially in writing.