The term "flash crowd" was coined by Larry Niven in his science fiction short story. He described it in one consequence not foreseen by the builders of the system was that with an immediate reporting of newsworthy events, tens of thousands of people worldwide would teleport to the scene of anything interesting, thus creating disorder and confusion.
Flash crowd then became a way to describe the Slashdot effect. But since 2005, the Slashdot term started to diminish when social media networks and others started gaining popularity. This was followed by Farked, Drudged, the Digg effect and Reddit effect or "hug of death".
They're common to describe exponential spikes in a website's traffic or server usage when a more popular website or celebrity links to it.
The sudden surge exceeds and overloads the smaller site's available bandwidth, resources or the ability of its servers to respond. This will then cause it to slow down or to even temporarily become unavailable.
The term was first used on the web by John Pettitt of Beyond.com in 1996. Although it was referred to be a modern phrase, the effect was anticipated as early as in 1956 in Alfred Bester's novel The Stars My Destination.
