A (long) while ago there was a lot of talk about the IRS doing text-mining for people that did not report income they got from e.g. ebay internet auctions. The German version of this attempt is called XPIDER (see also here and there) was just shown to be totally ineffective. After years of trying and spending millions they did not identify conclusive evidence to go after a single tax-evader. The German GAO (Bundesrechnungshof) is trying to find out what went wrong, why and who misspend all that money. I wonder if the more sophisticated web-crawling program the Canadian IRS is using (it’s called XENON as reported by Wired) is similarly effective …