A MARRIAGE is not just the union of two people. It is also the union of their data. And when they divorce, the data often gets spilled. The electorate is now witnessing a vivid example of this, arising from the separation of Anthony Weiner, a former congressman, and Huma Abedin, a top aide to presidential candidate Hillary Clinton. The FBI (Federal Bureau of Investigation) is poring over their emails with a presidential election just days away.

Divorce lawyers and data analysts said that less public versions of this story play out all the time. "The problem is, once they've already engaged in bad behaviour, it's out there," said John Slowiaczek, the president-elect of the American Academy of Matrimonial Lawyers. "You can't recapture it, you can't bury it."

No matter a person's level of technical skill, it can be difficult to hide digital behaviour from a spouse, a spouse's lawyers or, in Mr Weiner's case, federal investigators.