So, for those of you that are interested in alternate history, this particular story is about what would happen if herobrine were to escape into the physical world. By hacking into the internet, he would probably be able to do the following:
have access to nuclear launch codes,
have access to military drones,
he could do other things which I will address later. By using the drones, he would take out many U.S naval vessels, but not many as these vessels are very resilient and can take a lot of firepower from these drones. Having access to the nuclear launch codes he could nuke many cities such as Tokyo, Hong Kong, and cities on the east coast. Due to the plethora of nuclear warheads, he could destroy so many countries that he could just let the humans destroy each other as most of the world would be in total anarchy, of governmental instability. It would be sort of like a fallout scenario afterwords.

So it is a good thing that herobrine was defeated of humanity would never be the same.