<P> When Michael Jackson died in 2009, websites such as Google and Twitter slowed down or even crashed . Many sites' servers thought the requests were from a virus or spyware trying to cause a denial - of - service attack, warning users that their queries looked like "automated requests from a computer virus or spyware application". </P> <P> News sites and link sites--sites whose primary function is to provide links to interesting content elsewhere on the Internet--are most likely to cause this phenomenon . The canonical example is the Slashdot effect when receiving traffic from Slashdot . It is also known as "the Reddit hug of death" and "the Digg effect". </P> <P> Routers have also been known to create unintentional DoS attacks, as both D - Link and Netgear routers have overloaded NTP servers by flooding NTP servers without respecting the restrictions of client types or geographical limitations . </P> <P> Similar unintentional denials - of - service can also occur via other media, e.g. when a URL is mentioned on television . If a server is being indexed by Google or another search engine during peak periods of activity, or does not have a lot of available bandwidth while being indexed, it can also experience the effects of a DoS attack . </P>

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