Worth A Look: Summer Wars
However, this is not the story you might think from such an opening. The real story is around the fact the maths genius Kenji accidently hacks a security system and allows a mischevious entity to start taking over more and more systems until it threatens the entire world.
Saving the world takes a lot of help from a lot of people, and therein lies its charm. Grandma, especially, has an important role to play as she gets on the phone and sets about encouraging everyone in the family, and then other people whom she hasn't seen in years, to do their very best in the crisis. There's a family member who works for the ambulance who needs this encouragement because the enormity of the task is so daunting. Another works for the fire brigade and also needs encouragement.
This anime is as light a movie as any summer holiday bit of fun, but the spirit of cooperation between the huge family of characters, and the social networking community beyond them, is sweet.