That highly depends on the jurisdiction you're operating in / selling to.

While I'm not aware if anybody has ever been convicted for weirdly defined laws like that we for example have a "hacking paragraph" in Germany that outlaws software for the sole purpose of computer crimes. I'd imagine the UK has similar legal areas in lieu of their recent "kitchen knives are dangerous weapons, sometimes" controversy. It's not that hard to imagine somebody going after the manufacturer of such hardware and that blurb (or the ever famous "for educational purposes only") give them something to reasonably distance themselves from a user's actions.