Aside from their weak evidence base, digital cycle tracking technologies also come with serious risks, they write, including wasted time and labour, unwanted surveillance, risks to health data privacy, and may distract from or even threaten efforts to advance women’s health.

Never used one, never will but come one, wasted time is not a “serious risk”. They basically say it’s useless (which is not true, simply knowing when next cycle starts can be useful in itself, no need to sync diets or anything) but try to sensationalize it as something dangerous. Just say it’s bad for privacy, why make things up?