Hitprof, this is one of the features Fast had developed over the last two years. It's part of their attempts at adding natural language processing. Fast R & D has worked on that for quite a while. Results where mixed IMO. For many queries it has worked fantastic, but sometimes it can collide with the users intentions.
Fast is one of the few huge web search engines which has actively pursued the implemenatation of NLP. Their achievements are now part of the OV resources. Hope they make something out of it.
BTW: you can turn that feature on and off from the Preferences section, where you can completely customize the whole engine. Lots of stuff to explore there.