It was bad enough that 80 million Facebook users allegedly had their data harvested by a company building a platform to try to sway the US election – but now broader concerns are emerging over the privacy and security of such information.

New Scientist revealed this week that information on millions of Facebook users, gathered by researchers in the UK, was left exposed online. Days before, The New York Times reported that Swedish and Polish researchers had amassed data on 368 million Facebook users. The researchers in …