Connection problems can happen at many points between your computer and the host computer. The biggest problem however are DDoS attacks, or Denial of Service attacks. You can view a real-time map showing attacks currently underway across the globe at www.akamai.com (then click the “Attacks” button to reveal areas currently under attack).
Denial of Service happens when a server receives thousands, possibly tens of thousands, of “fake” connection requests simultaneously. These situations are caused by people who deliberately attack servers through tools like botnets. As a result, the servers are overwhelmed and cannot deliver your website files to you.
One recent analysis revealed the origin of attacks as China (39.08 % of attacks), Mexico (27.32 %), Russia (7.58 %), Korea (7.29 %) and France (6.50 %). Another source claims China 41%, followed by Mexico, Germany and Iran. Several weeks ago, we experienced a Friday morning when almost a third of servers in North America were affected at the same time.
The origin of the attacks shifts constantly and Denial of Service attacks grow more and more complex in scope. It is the largest issue currently facing the Internet today. It particularly affects countries like the United States that have extensive network infrastructures, and particularly the West Coast of North America. These areas are typically more susceptible to being selected as targets by malicious groups who seek the unauthorized use and abuse of those network resources.
Why do people launch these attacks? The people behind them include crime gangs, extortion groups, groups disguising other crimes, hacker groups, vandals and mischief makers. One type of attack, known as cyber “hacktivism”, involves attacks by people against certain banks, ecommerce and government sites and corporate sites just because the sites don’t serve their political, religious or ideological values.
Websites may be remembered one day as a luxury of the early 21st century. Denial of Service has been described as an “arms race” between the hackers and the companies trying to solve the issues.
Resources
http://copperegg.com/ddos-attacks-quicker-and-more-frequent/