Wikipedia was down today for few hours and was showing below error message while checking homepage of wikipedia. Many sites reported this incidence including Cnet.
Even When we check direct link of articles, few articles are displaying correctly but few articles shows wrong articles or shows same error page.
Wikipedia is largest, free, multilingual encyclopedia with more than 2 Crores articles. Its ranking sixth most popular websites in world by Alexa.
This is just coincidence that 8th ranked Twitter was down on 26th July 2012 while 6th ranked Wikipedia is down on 6th August 2012. Whats next on 16th August? 4th Ranked Yahoo.com :)?
BTW: Twitter Error message was weird while Wikipedia has at least formatted error message. lol.
You can check Top 500 websites here. http://www.alexa.com/topsites/global