Enfold Systems recently announced how Oxfam's Plone-based website helped Oxfam respond to the Tsunami tragedy by rapidly publishing information about relief efforts and raising $14 million in donations. The article also discusses how nicely the system scaled to the increased traffic. From the article:
When the Tsunami crisis occurred, the system was put to the test. "In the course of ten days during the Tsunami crisis, Oxfam had almost half of its typical yearly visits, and almost 1/3 of its yearly bandwidth - the system performed beautifully", said Internet Manager Nicholas Rabinowitz. "Our public website offered timely, critical content to our users, while providing a solid gateway to our online donation system."