Many private Polish TV channels and radio stations fell silent and online sites and newspapers ran black front pages on Wednesday in a concerted protest over a planned tax that critics fear will weaken or destroy some media.
TVN and Polsat TV went black with the message "find out what the world will look like without independent media".
Top news websites had black front pages with the slogan "media without choice".
Plans for a tax on ad revenue were set out earlier this month.
Poland's nationalist government describes the proposed levy as a "solidarity fee" and says the aim is to raise money for the National Health Fund, and for culture, struggling with the coronavirus epidemic.
In an open letter to the authorities ahead of the blackout, dozens of private media companies said they believed "such drastic action is necessary because without free media there is no free choice, and without free choice, there is no freedom".
A day without independent media
When Poles woke up this morning and tuned into the morning news or soap opera all they saw was a black screen with the words, "this is where your favourite programme was supposed to be".
Radio stations apologised to listeners, saying they wanted to show Poles what 24 hours was like without independent media. Private media owners said the planned advertising tax would add $270m (£195m; €220m) annually to their costs and could send many companies struggling with falling revenues under.
The proposal has increased concerns about the fate of media pluralism in Poland. Public television, TVP, has already become a government mouthpiece, with the evening news daily praising its achievements. The government says there's too much foreign-owned media in Poland.
Recently, Poland's largest state-controlled oil refiner, PKN Orlen, said it was buying the country's leading regional media company, Polska Press, from its German owners, saying it makes sound business sense.
In their open letter, the private media companies said that while they faced $270m in additional costs because of the levy, public media received twice as much a year from taxpayers.
Government spokesman Piotr Müller told public broadcaster TVP Info that the proposed law was still at an early stage and a draft had not even been approved by ministers.
Prime Minister Mateusz Morawiecki has described the levy as part of broader European attempts to tax digital tech giants such as Facebook and Google. However, the Polish proposals would also apply to domestic players in the digital market.
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