Insane Walmart gun, 1200 rounds a minute :s

I Googled Walmart USA, then searched guns. It took literally seconds to find this:

link

Not that I know anything about guns, there might be better ones on that page I dunno, but the 1,200 rounds a minute was pretty out there. WTF do people need something like that for?

Anyway it was surprising that the recent deaths of all those kids and teachers in the US, although they were hit multiple times, took only 2 minutes. That's insane.