2160p is not totally correct Devin, since the panels are fed by four 1080p signals, not one progressive signal. I believe the correct definition used when these panels first came to market a few years ago was QFHD, or quad-full HD. These panels are also unsuitable for video (hence all the demos showing still images) because there is as yet no device available that can feed/process QFHD resolutions at motion picture frame rates. It will take many years before US broadcast TV even approaches that resolution, and at the moment, unless you have a beefy set of video cards in your workstation to feed those four 1080p signals in parallel, you won't be hooking these monitors into anything else.
Engineering schematics, artwork, mapping, satellite imaging etc. is what these panels are being used for.