Back in June 2012, Google became one of the first big tech firms to announce that it would notify users it suspected of being targeted by state-sponsored attacks. Earlier this week, across the space of 24 hours, a huge number of prominent journalists and professors from around the world received these warnings.

Some of those affected include Nobel Prize-winning economist and New York Times columnist Paul Krugman, New York magazine's Jonathan Chait, Politico's Julia Ioffe, GQ's special correspondent Keith Olbermann, Vox's Ezra Klein, Yahoo News' Garance Franke-Ruta, and former speechwriter for President Barack Obama, Jon Lovett. Ars Technica reports that several security industry professionals also received the same warning.

The red banners reads: "Warning: Google may have detected government-backed attackers trying to steal your password," and includes a link leading to an advice page on how to secure accounts. Reports state that some of the people who received the message were already using two-factor authentication.

A Google spokesperson said the warnings were likely the result of hacking attempts made over the last month, rather than more recently. The company delays informing users that they have been targetted so attackers can’t learn security researchers’ detection methods. However, if a breach is successful, Google informs the victim straight away.

While Google has sent out these warnings in the past, the sheer number of people who received them within a 24-hour period is suspicious, to say the least.

Google hasn’t indicated who might have been behind the attacks but, assuming they took place around the time of the US election, they could relate to a spear phishing campaign tied to Russian government hackers that began just after Trump’s victory.