At about 9.30pm on Easter Monday, in the small Dutch town of Almere near Amsterdam, the fire brigade was called to put out a blaze at a large telecoms mast—the second fire of its kind that night in the area.

Though neither of the Almere towers were equipped with any of the latest 5G telecoms equipment—in fact one was designed only for use by the emergency services—authorities soon concluded that the fires were perpetrated by vandals acting in the name of an unusual theory: that 5G networks have contributed to the coronavirus pandemic.

The Dutch mast fires are just the latest escalation in a series of similar attacks that have swept across the UK and Europe in recent weeks. Having first gained momentum online in early January, the 5G conspiracy theory—which alleges, among other things, that COVID-19 has either been caused by the frequencies used for the new wireless technology, or that those signals impair the human immune system—has spilled rapidly into the offline world.