which sounds like it came from React's "dangerouslySetInnerHTML", per the comment you replied to.

I think people used similar prefixes for a long time. For example, Haskell has had `unsafePerformIO` since the 90's... and MSFT's Hungarian notation was also similar, though it used abbreviations for things like "unsafe" (not "dangerous"). Perhaps React was the most famous case of using "dangerously" though.