Another possibility is that you and some others have a misbehaving popup blocker or ad blocker. Or even that some ISPs briefly experimented with some blocking software.
Or perhaps there is a new virus chewing on the internet. At any rate, I don't think it affected everyone everywhere.
Sometimes your reasoning bothers me...do you really think that we tried to get an image with out refreshing several times? Do your really think that going from country to country we had anything in our cache for those sites? If we had it would have shown and not remained blank. Do you think that we bought our first computer yesterday? Would it occur to you, that no one else noticed perhaps because of the cache, and who on ghod´s green earth would assume anything was wrong because they did not get an image?
When presented with six facts, try and get your mind around all of them, not one, not two, and then make a educated guess as to cause. Then you might reconsider your impossible theory, and concede that the government could take the Net down if it wanted to, not that it did.
Check the time, check the duration, check the backbones, nodes, servers involved. Is there a commonality across the world. If you think there is, and no redundancy involved, then I suggest you would have to rethink you impossible remark. Check how many people would be in two countries working together, so that a instant comparison could be made in those six minutes. And finally, tell me how many of those would be freepers and post their experience on this thread, when 95% of them would have been in bed.
You say it is impossible, so if it happened, we would have a problem wouldn´t we?