makes KPIs, a measuring tool, the target which as any statistician will tell you that when you make the measurement a target it ceases to be a good measuring tool

This came up recently elsewhere and is known as “Goodhart’s Law”

Story title is clickbait. Read this (short) Wikipedia article to get a quick summary

tl;dr the privacy tool in question mixes cryptocurrency funds with other users funds and hence the US government alleged this was a money laundering service