I'm no lawyer but this does not say the FBI can hack anyone anywhere in the world. It explicit says a judge may authorize the search warrant if, among other things (mostly related to where the target is within the US):

(B) the premises—no matter who owns them—of a United States diplomatic or consular mission in a foreign state, including any appurtenant building, part of a building, or land used for the mission's purposes; or

(C) a residence and any appurtenant land owned or leased by the United States and used by United States personnel assigned to a United States diplomatic or consular mission in a foreign state.

So it says clearly "owned, leased, used by... US diplomatic or consular mission in a foreign state". Not that any laws have prevented the FBI/NSA from doing any of this already.

Apparently, citizens of other countries should not be worried (with this particular law). Could anyone with more knowledge in this area double check this?