Don't post on Facebook unless you are prepared to face the consequences

The platform's advertising software is beautifully engineered but it often produces ugly results

Earlier this month Anne Borden King posted news on her Facebook page that she had been diagnosed with breast cancer. Since then, she reports, my Facebook feed has featured ads for alternative cancer care'. The ads, which were new to my timeline, promote everything from cumin seeds to colloidal silver as cancer treatments. Some ads promise luxury clinics - or even nontoxic cancer therapies' on a beach in Mexico."

The irony is that King is the last person likely to fall for this crap. She's a consultant for the watchdog group Bad Science Watch and a co-founder of the Campaign Against Phony Autism Cures. So she effortlessly recognised the telltale indicators of pseudoscience marketing - unproven and sometimes dangerous treatments, promising simplistic solutions and support. In that sense she is the polar opposite of, say, Donald Trump.