There are several reports around the web about a new search bot by Microsoft that is causing major issues for web servers. The bot is named adidxbot and the useragent looks like this: adidxbot/1.1 (+http://search.msn.com/msnbot.htm).
This bot has been on the loose since the middle of May. There are threads at WebmasterWorld and Bing Community with complaints about this bot. The bot reportedly indexes and crawls incredibly quickly, with no remorse on the web server. This can cause servers to see spikes of CPU usage and slow down the normal visitors from using the site. In addition, the spider does not obey the crawl delay command.
A Bing representative said the fix was just released this morning and the bot should no longer cause issues for webmasters. Brent Young of the Bing team said:
I just received word that they fixed the bug that was causing this. If you are still experiencing issues, please email me at firstname.lastname@example.org
I hope so.