As senators squabble about the theoretical vulnerability of those who use TikTok, they might want to find more time to give greater consideration to a clear and present danger erupting within the US health-care system: the continuing cyberattack that has put at risk the medical data of 79 million Americans and thrown health-care services into disarray.

Because of the frequency of attacks on health-care systems, particularly those involving ransomware, news of the breach of UnitedHealth Group’s Change Healthcare, attributed to a notorious Russian hacking group, has barely risen above a murmur.