Apparently M$ was quite irritated that this existed, piggy backing on the popularity of their HALO franchise:
Liberty Ammunition removed all mention of HALO from their website, rebranding the ammunition simply as “civil-defense” now.
If you wanted to get some for your collection though, Midway USA still has some 9mm +P for $20 per box.
There’s a huge article on this ammunition over at Kotaku you can check out for more information.
Hat tip: hocklermp5