1) What do you think would happen?
Well, I guess cellphones/iPods will have to be an even bigger deal than it is now!
iTunes or Spotify wouldn't be available anymore, so time to purchase an iPod including purchasing actual albums of your favorite artists(Really, does anyone buy any albums these days?).
Games? Well, I guess we're back to single player games for the consoles/PC. Time to invest in some real life friends if you want to play multiplayer, cooperatively or competitively.
2) How would you react?
I would hate it at first, because of where I'm from, there's literally nothing to do with anyone & I'm not a big fan of bars(Tired of people suggesting me that). >:( Most of my friends are very busy with work nor have moved out of town/state while gas is expensive to do too much traveling here & there.
I love interacting with others outside of my hometown, state & hell, even outside of the US! I pretty much know/see a lot of the same people where I'm from. So it would be a huge deal to lose that opportunity to keep in touch with others.
Online gaming has become a huge thing for the gaming world. So it'll be tough to lose the "online" aspect. I personally love it, but I do enjoy tons of Single Player games so it wouldn't bother me. The multiplayer games wouldn't be the same for me without internet/online however. Unless your Diablo III for the Xbox 360, I enjoy playing it locally even.
Music. Oh my music. I have a lot of music downloaded anyways so as long as I keep them saved on my USB Drive, I'm good. Just has to keep up to date on buying future albums of my favorite artists. (Which I already have started doing basically, Ariana Grande<3).
Oh & as for TV shows, I guess I simply can just go back to actually watching them on TV on a scheduled time(I usually do but with all the shows I like to keep up with, too many shows to watch at once & it's just easier to go back & stream them online, since I no longer have Time Warner Cable) If I miss it, I'll be disappointed but will have to wait. What else could I do without internet right? Since it takes a year for DVD/Bluray to be released after the season's end anyway. Same goes for movies.
3) How would the world react, more importantly?
Ehh, I would honestly think depression, suicide & crimes would be involved majorly if this is the case. The current generation has been pretty reliable on technology, because of how heavy technology is among us now. & Technology generally has online/internet features! Its a huge part of our lives. I live 30 minutes away from an Amish county. When I see an Amish person or a group of them, I often think to myself & even ask my family or friends, "How different do you think life would be if we were in their shoes?" Of course, I get no answers better than "I don't know." x)
But if the people survived 50 years ago without that much internet, then why can't we? It just depends on how each individual handles it, really.