If even President Trump’s own devices are not immune to hackers, what of those employed by the informal advisers with whom he regularly huddles at his various estates? ProPublica has reported that a group of three Mar-a-Lago members — a businessman, a doctor and a lawyer — exercise huge sway over decision-making regarding the Department of Veterans Affairs. How secure are their devices and the devices of other advisers with influence on other matters?

For that matter, how secure is the Mar-a-Lago wireless network used by the club’s influential members and guests, many of them friends of the president? What about the club staff’s computers? It is perhaps telling that one Mar-a-Lago visitor was reportedly able to gain sufficient access to the staff computer system to change its screen saver to an obscene message about the president.

Secretary of State Mike Pompeo was quick to describe Zhang’s arrest as an indication of “the threat that China poses,” strongly suggesting that the State Department suspects her of spying. Yet Chinese influence-peddlers, some of them with unabashed connections to the Communist Party, continue to sell invitations to Mar-a-Lago online with impunity. And no wonder, given the lax security there. The Secret Service can operate checkpoints and try to monitor visitors, but Mar-a-Lago isn’t Camp David; it’s a venue rented out for wedding parties in the Donald J. Trump Grand Ballroom.