rogerd - 3:31 pm on Mar 3, 2012 (gmt 0)
If this is indeed the company identified above, my best guess is that it is collection of comparative data that was assumed to benign because it's not actually taking sites down. The nimrods behind it are likely unaware of the impact on engagement metrics, Adsense, and comparative analytics.
Or, it could be a screwup that got magnified by the size of the network. E.g., a link gets followed from somewhere, and then filters into some kind of a list that launches the bot army.
All total speculation.