history flow work) tried to measure how quickly vandalism on Wikipedia was identified and corrected. They searched for pages where suddenly all of the content disappeared or a huge amount was deleted. They found that the median time for such a page to be restored was 5 minutes. This did not take into the account the process that where Wikipedians often refactor or move pages and redirect them which would show a similar behavior. So the median time is probably less than 5 minutes. In the context of our discussion about Wikipedia authority, I think this is quite an interesting and impressive statistic.