Depending which way you lean, either "Computer Numerical Control" (very precise cutting of material) or "Consensual NonConsent" (rough sex, basically - there are better words for it but not without triggering things).
My wife recently told me about some post she saw online. In this post, a very innocent man discussed his new CNC setup, then was quite surprised by the dichotomous responses he received.
Fair enough. My email signature used to include a sentence that included words like "bloody" and "slaughter" since gmail didn't advertise alongside notifications of a tragedy. I doubt they're so conscientious these days, though.