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 [1] XPIDER (see also [2] here and [3] 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 [4] XENON as reported by Wired) is similarly effective …