It's enough to get their lawyers after you and cost you a ton of money in legal costs to fight even if the legality behind it may be dubious. I'd say the recent Nintendo filing against Yuzu is a similar case for comparison.

Is Yuzu liable for piracy because they create an emulator and create guides on how to get licensed games working on it? Who knows. Could Nintendo throw lawyers at them endlessly until they submit, or even set a terrible precedent if Yuzu lost? Definitely. Which is why Yuzu just settled it, which in effect lets Nintendo win through their dubious claims.