I've also been following the news (I'm Hungarian). To clarify, this planned tax is for ISPs, but ultimately, it means that the end user would have to pay more one way or the other.
Besides the fact that people are already heavily taxed in this country, my biggest issue with this planned tax is that it
1) could possibly restrict informational freedom by giving less people the possibility to pay the monthly Internet fee
2) would hold back the adoption of technological advancements (audio and video streaming, online storage, etc.)
And yes, we are doing something about this. The plan was announced this afternoon, and there is already a protest being arranged on Facebook where 6k people said "going".
https://www.facebook.com/events/881301788579327
The online press is full of articles on the issue and so is Twitter and Facebook.
Hopefully Anonymous knows about this already, or will soon.
One more thing to mention: there was another big piece of news today about 6 Hungarian citizens that were barred from entering the United States. The whole thing is a mess, and very little is known, but one thing is certain: these 6 people were all public officials or affiliated with the Hungarian government and were involved in some sort of political corruption.
The Internet tax plan could potentially be a fraud to draw people's attention away from this corruption issue. Whatever is the case, Hungarians should give attention to both issues and the connection between them.