A transgender-issues activist and Democratic candidate for Congress says the advent of the space tourism industry could give private corporations a “frightening amount of power” to destroy the Earth with rocks because of the Moon’s military importance.

Brianna Wu, a prominent “social justice warrior” in the “Gamergate” controversy who now is running for the House seat in Massachusetts’ 8th District, suggested in a since-deleted tweet that companies could drop rocks from the Moon.

“The moon is probably the most tactically valuable military ground for earth,” the tweet said. “Rocks dropped from there have power of 100s of nuclear bombs.”

SpaceX announced Monday it is planning to launch a tourism venture to the Moon in 2018.

After users on social media questioned her scientific literacy, the congressional candidate clarified that the tweet was “talking about dropping [rocks] into our gravity well.”

Small space rocks can indeed do nuclear-weapons-scale damage if hitting the Earth at orbital speeds. But launching one from the moon, even setting aside issues of aiming, would still require escaping the satellite’s gravitational field, a task that requires the power and thrust contained in a huge rocket.

One Internet wit posted on Twitter the footage of an astronaut hitting a golf ball on the moon, with the words: “Alan Shepard: FORE! [destroys Leningrad].”

Ms. Wu blamed criticism of her on sexism: “that’s the danger of being a woman on the internet!” she exclaimed.

“Like, you all can make fun of that statement, but it will still be true,” another Wu tweet said. “This is why the militarization of space is so dangerous.”