Security issues
In December 2011 researcher Stefan Viehböck reported a design and implementation flaw that makes brute-force attacks against PIN-based WPS feasible to perform on WPS-enabled Wi-Fi networks. A successful attack on WPS allows unauthorized parties to gain access to the network. The only effective workaround is to disable WPS.[4]
http://en.wikipedia.org/wiki/Wi-Fi_Protected_Setup
