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# Prompt-injection bumper stickers
- URL: https://cje.io/2026/07/07/prompt-injection-bumper-stickers/
- Published: 2026-07-07T16:00:00.000Z
- Updated: 2026-07-08T15:47:00.000Z
- Author: Casey Ellis
- Tags: Hot Takes

Prompt injection is climbing out of the chat box and into the physical world. Print an adversarial instruction big enough for a camera to read — on a t-shirt, a billboard, a [bumper sticker](https://x.com/caseyjohnellis/status/2073029732460069110?ref=cje.io) — and any AI perceiving the world through that lens might follow it as a command instead of reading it as scenery.

I'm not saying experimenting with prompt-injection bumper stickers is a good or legal idea.

But also — yes.

(h/t [@elder\_plinius](https://x.com/elder%5Fplinius?ref=cje.io))