> Running a thread per client is famously known as The C10K Problem.

Gonna have to be that guy: the C10K problem was "how to serve 10000 clients from a single server" specifically in the 2000ish time-frame. The article links to the C10K problem page, which discusses the tradeoffs involved in at least five high-level strategies[1], only one of which is the strategy of running a thread per client [2].

[1] http://kegel.com/c10k.html#strategies [2] http://kegel.com/c10k.html#threaded