The problem is when people fail to distinguish "helpful assumptions" from "actual facts"... I have just today gutted some worse-than-useless GeoIP functionality

The problem is when people fail to distinguish "helpful assumptions" from "actual facts"... I have just today gutted some worse-than-useless GeoIP functionality from a form that was facing customers of our organization so it could guess at their country, language, and city without asking. BI guys put in the feature request some years ago so they could make pretty maps (but ultimately take no actionable steps based on these), and call center were then taking these guesses as facts (think getting a call and having someone chummy ask "Hey, how's the weather in <city you don't live in>" in the wrong language...). What's worse is we then added some user-facing fields asking for the location information, and it was impossible to tell apart user-supplied info from the IP-derived info! It took fighting with BA and BI, but we finally decided it was stupid and were able to simply remove it. (BI will have to "fix their maps" by doing their own assumptions, outside of the application)