Twitter used an anti-fake news law France passed in 2018 to block the French government’s social media campaign to get citizens to vote early in an upcoming election.

France passed a law in December 2018 requiring online political campaigns to declare who paid for them, and how much was spent. Twitter is now using the law to black out the government’s campaign encouraging voters to register for the European elections ahead of the deadline.

The French government information service operated the campaign and planned to pay for sponsored tweets, according to news agency AFP. French officials, who have long threatened to censor big tech companies, were shocked that Twitter would obey the letter of the new law instead of finding a way to deal with its vagaries.

One MP, Naïma Moutchou, thought it was an April Fool’s joke. “I believed in an April fool! ⁦⁦⁦⁦@Twitter ⁩ blocks the public campaign for registration on the voters lists! For not having to adhere to the anti-transparency rules #FakeNews. Appalling and illegal,” she said on Twitter Monday.

France’s Interior Minister Christophe Castanter also vented frustration. “Twitter’s priority should be to fight content that glorifies terrorism. Not campaigns to register on the electoral lists of a democratic republic,” he said in a tweet Monday.

The new French law is designed to make clear who is paying for advertisements. It requires online platforms to provide “fair, clear and transparent” information about the company or person in an accessible database format. Big tech companies have been battered around by European countries recently.

European Union regulators fined Google a hefty $1.7 billion in March, for instance, on the basis that the Silicon Valley giant violated various anti-trust laws. European officials claimed Google engaged in illegal practices in a bid to monopolize advertising markets.