Thousands of protesters in the Hungarian capital Budapest have demanded a halt to a proposed law which would place a tax on internet use.
Demonstrators held their mobile phones aloft outside the economy ministry and hurled old computer parts at the gates of the ruling Fidesz party.
Campaigners say the legislation is "anti-democratic" and will hit the poor.
Ministers have promised to place a cap on the tax.
The draft law, proposed by the government of Prime Minister Viktor Orban, would levy a fee of 150 forints (£0.40; €0.50; $0.60) per gigabyte of data traffic.
But many of those who gathered in Budapest on Sunday are worried about the consequences.
Rally organisers said the move "follows a wave of alarming anti-democratic measures by Orban that is pushing Hungary even further adrift from Europe".
In response, the ruling Fidesz party said it would submit an amendment to the law ensuring that monthly payments of the tax were capped at 700 forints.
Despite divisions within Fidesz, Mr Orban commands broad popularity in Hungary and the party has won three elections this year.
But his opponents have decried what they see as his increasingly authoritarian style and his closeness to Russian President Vladimir Putin.