See this talk page:
http://en.wikipedia.org/wiki/User_talk:189.148.6.25
The poster purports to be a journalist experimenting with putting
toxic links on Wikipedia to see who will follow them.
Although his actions were IMO dickish, he has some point: is there any
reason to allow .exe links on WMF sites? Is there a clean method to
disable them? Is this a bad idea for any reason? What should default
settings be in MediaWiki itself? etc., etc.
- d.