Well, it is a quite current subject, as I can find many things about it just through making a search on Google. So after having been captivated by this date for a few days, I will give you a probable version of it. Because I think something will really happen on December 21, or not.
My scenario of this 21st December is a digital holocaust (I have found no satisfying term to describe it) making mechanically other events happen: one country, which has build a defense against other country’s attack is attacked. This system strikes back by attacking the country from which the attack has been lead, leading the Internet connection to be overflooded and thus unable to complete anything for hours. But the system has a side effect making it strike another country. The latter attacks but due to side effect, other countries are also affected. At each attack the entire bandwidth of a country is affected to “war effort”.
Sure, during that date, many things will happen: many sects on this world will commit collective suicide or occupy massively a place that is not made for. Many nations will have their Internet connection cut, so they can not be aware of what’s happening, even in their own country. Most people will be unable to telephone due to the Net War. Everyone will be disconnected to each other, and breaking news won’t have many readers.
Cut to the rest of the world, the markets of London, Paris, Tokyo or New York will go mad: the price of precious and rare raw materials is increasing, making the insecurity growing: you will likely to be killed for detaining on you precious items such as telephone, or golden artefacts (rings, necklaces…). In response to this, the government will increase the number of policemen operating in cities, but this has quite huge repercussion on the State’s budget, making national debt increase. Debt increase is not appreciated by the markets, and already very fragile States will be going to lack money to pay all their civil servants. To avoid this, taxes will be increased in order to have some funds to make the State and all its institution work… temporarily.
Tax increases are never appreciated, even more in economic crisis. In fragile countries (Spain, Greece, Portugal…), the situation will turn into civil war. As money got from taxes goes decreasing. As there is no money anymore to pay them, civil servants are fired, and become officially unemployed. Actually many people will do unreported employment. For the few people still working reportedly, dissatisfaction towards the government policy will grow, leading to more and more frequent and violent demonstrations. To be able to contain demonstrations, the police will become more and more violent, making demontrations become carnage and bloodshed. But due to markets holding governments by their balls tax will increase again and again. But without any effect as already more than 80% of people have at least one unreported work. This is a great loss for taxes, so these 80% will be stalked by the government, leading to civil war.
Overflooded by stalking workers trying to survive, and by robbers breaking everyone’s home, policemen no longer grant security in cities. So more and more people leave these cities for the surrounding countrysides. People will be organised in small communities, with their own militia to defend the community’s property. The State no longer exists. It is the end of a word: the one we knew before.