Looks like MSN is being targeted by hackers. I got the message below when I tried searching MSN for link:http://forums.absoft.com/viewtopic.php?pid=1932
We are seeing an increased volume of traffic by some malware software. In order to protect our customers from damage from that malware, we are blocking your query. A few legitimate queries may get flagged, and for that we apologize. Please be assured that we are hard at work on this problem and hope to get it resolved even better as soon as possible.
If you are using phpBB, please check out the phpBB downloads site http://www.phpbb.com/downloads.php and make sure you are not vulnerable.
- MSN Search Team
I did a search on Google to find out more, and apparently this has been seen by others:
I reported about this problem previously with Google. Hopefully MSN is not going to get as aggressive as Google about denying service to automated queries.