the site was being 'crawled' by search engine 'bots' from about 9 or more different search engines (including Yahoo China?! and a weird 3D search engine http://www.searchme.com )
Basically these 'bots' were hitting up every single page on the site and making a note of what everything is. There are about quarter of a million pages on DiS so this took a helluva long time.
Why did they did it in the morning? Because it's the middle of the night in America and obviously they can't slow down American internet users.
So yeah, sorry (not that I need to apologise), it also massively fucked me off too.