Why didn't the army annihilate the giants?
So the army locates a group of child abductors/murderers, but all they do is capture them and relocate them to a deserted island??
After rescuing the girl and the friendly giant, why not just drop a few MOABs on them, or maybe a tactical nuke??
Then again, this is a family movie, so I suppose showing the giants' flesh combusting and then burnt to ashes (Terminator 2), or seeing their bodies shredded into bloody pieces might be a bit much.
Then again, this movie lost money. To make more money on it, they could put out an R-rated studio cut on DVD with an alternate ending showing the giants try to battle against cluster bombs, miniguns, napalm, and cruise missles. Just add a 30 minute CGI battle scene to the end. As a bonus, maybe they could do another alternate ending where the battling giants and army are hit by a warp storm, transporting them to Mars in the Doom universe. Giants vs Cyberdemons! Then the army could find a REAL BFG-9000 and show the giants what BFG really stands for! Yeah!!!