At least they won't get angry and accuse you of heartlessly trying to kill them in order to save a few dollars on tensor fields.
Who heartlessly kicks Aziz Ansari into a hole, causing him to plummet to his death, instead of trying to save him?
Old English heortleas "dispirited, dejected;" see heart + -less. In Middle English with expanded senses "lacking in courage; foolish; listless; half-hearted; sluggish." Sense of "callous, cruel" is not certainly attested before Shelley used it in 1816. Literal meaning "lacking a heart, lifeless" (mid-15c.) is rare. Related: Heartlessly; heartlessness.