The government using a zombie virus is unlikely as they would lose valuable tax dollars, votes and resources. NOW a pharmaceutical company spreading a disease is another story, they could make tons of money not curing it but developing a medication to prevent the effects of zombification. This will all be fine and good until Skynet becomes self aware and goes bananas that the human race's greatest achievement is Justin Beiber. Realizing that evolution has stalled and that a world wide intellectual holocaust is being waged by Jeresy Shore and Fox News, Skynet will launch nuclear warheads at Russia, Santa Clause and Chuck Norris. However the crisis will be averted when it turns out that Iron Maiden along with the Freddie Mercury riding the Loch Ness monster are throwing a concert in Moscow. They will use the power of METAL to prevent the missiles from doing any harm and somehow causing it to rain beer and women. Sadly though the real destruction will come when the North Pole and Santa is destroyed, while Chuck Norris is visiting. Chuck Norris being part Chuck and part Norris will be able to withstand the blast. Sadly Santa won't and Chuck will mourn the death of his younger brother Santa.(You think they could have such sweet beards and not be related? The Trilateral Commission must have gotten to you.) Chuck Norris will ascend then to Valhalla AKA Chuck Norris Mega Death Ranch and being the Ragnarok that will shake earth to its very core and destroy the world unless the Space Pope and Hugh Hefner provide an offering of virgins, beef jerky, and grain alcohol to appease the vengeful Norris. Then he will return to Valhalla and enter his Odin Sleep and slumber until Hollywood green lights the Walker Texas Ranger Reunion Show.
The aliens from Uranus.