P arts of the internet are going dark. In the Netherlands, government websites, including its digital ID login service, have become unavailable. Finland has taken public services offline, and Wikimedia, the organisation behind Wikipedia, has switched off some of its systems too.

This sounds like the results of a cyber-attack. In most instances, however, the people running the sites deliberately switched them off because the alternative – keeping them online – was too risky. The future is here, and suddenly much of our digital infrastructure is looking very fragile.

The websites were turned off because of two serious security vulnerabilities in PHP , a programming language that is used by about 70% of websites that we can track. Those vulnerabilities in effect gave hackers an open window through which to climb and loot everything within. That could mean an attacker getting into an online shop, stealing customers’ addresses and passwords, or changing its checkout page to harvest card details.…