Microsoft's Personal Search Engine

Microsoft is apparently toying with an idea around developing a personalized search function linked back to MSN Search using the content of information stored on your PC. The searches are supposed to be personalized only the user's benefit.

Projects on display during a Microsoft Research event yesterday included a method for personalizing Web search results based on the contents of the files on an individual user's computer hard drive More...

Apparently, the idea revolves around using MSN Desktop Search to acquire said personal data. This would then be fed to MSN Search and personalized search based on the contents of your computer would be delivered. Unlike Google Desktop which claims not to port data back to their servers (see privacy policy), this Microsoft approach seems to have the capabilites to mine information en masse.

What are your thoughts concerning MSN's approach to such a personalized search? This seems rather intrusive to us...