In mid-February, one year after Russia’s full-scale invasion of Ukraine, the Finnish internet was hit with a deluge of near-identical messages chastizing Finland’s ambitions to join western security alliance NATO.

On social media platforms like Twitter, an army of users parroted the same sentence: “NATO can’t save Finland.” Some posts received tens of thousands of views in the lead-up to the country’s admission to NATO on April 4.

But there was a catch: the sentence that spread like wildfire was grammatically incorrect. In the Finnish language, there are two verbs that mean “to save.” One means to rescue, and the other means to save in the form of recording or storing. The viral phrase used the latter.

The erroneous use of the verb, alongside the proliferation of seemingly fake accounts tweeting the slogan — many were only a few months or weeks old — alerted the Finnish public that the viral message was not the product of an organic uprising at home. The origin of the campaign hasn’t been determined, but many believe it was an act of disruption, or disinformation warfare, likely stemming from pro-Kremlin actors using bots, paid trolls and influencers relying on Google Translate to carry out the failed campaign.

What began as an effort to stoke discord in Finnish society and discredit Finland’s efforts to join NATO became a running joke in the nation, inspiring a flood of wisecracks and memes. The country’s public broadcaster Yle published a story in late February with a headline that read: “Finnish grammar foils pro-Russia trolls.”