The E.U. has taken a far more aggressive regulatory approach to government-backed disinformation than the United States has. The Digital Services Act, which went into effect for the biggest social media companies Aug. 25, requires them to assess the risk of false information,stop the worst from being boosted by algorithms and subject their performance to auditing. Separately, European sanctions on Russian state media have prompted YouTube and other platforms to ban the likes of RT, the Russian news outlet formerly known as Russia Today that was once one of the most-followed channels.

The study is the starkest indication yet that the legal and voluntary measures are not getting the job done, following June warnings from E.U. Commissioner Thierry Breton that X had work to do to avoid potentially massive fines under the DSA. The research was conducted by nonprofit analysis group Reset, which advocates for greater oversight of digital platforms.