Really good description
of what might happen.
What happened in Denmark.
7 years ago we got a child pornography filter on the Internet in Denmark. Some people said that it was a bad idea, but others said these people were just paedophiles, or trying to help paedophiles. Some people said that it was against our constitution, which it was. So the censorship was implemented in a way so it was formally (but not in reality) voluntary, which ensured that it was not formally a violation of our constitution.
Some people warned that once the censorship infrastructure was in place, it would most likely be used to censor other things. But they were told "Never! This is ONLY to prevent this horrible crime, and will never be used for other censorship."
Fast-forward a few years, and the Danish recording industry did not like allofmp3.com, so they went to court to get a court order against the Danish ISPs to start censoring allofmp3 off the Danish Internet. The judge basically said "ahh, you already have the infrastructure in place, so there will be no extra cost", and issued the order to censor allofmp3.com. It was not a violation of our constitution because it was ordered by a judge.
Since then other "pirate" sites have been censored. Most notably The Pirate Bay, which found out that the court would not even allow them to speak their case in court, or even submit a written brief.
Then our politicians found out that they wanted to protect and expand income from taxes. In particular the high taxes gambling providers pay. The official excuse was to limit the horrible disease of ludomania. So they decided that foreign gambling providers had to pay the taxes in Denmark too if they were on the Internet and could be seen in Denmark. If they refused to pay taxes, they should be censored off the Danish internet. So they passed a law saying that if a foreign gambling provider refused to pay taxes in Denmark, a court would - on the request of our government - have to order ISPs to censor its sites off the net, and payment processors to block all payments to it. If an ISP does not censor, or a payment processor or bank does not block payment, hefty fines are issued.
Now our politicians worry that some foreign companies selling medicines on the net are not licensed to sell medicines in Denmark. So they are preparing new legislation that will censor these sites off the net, and block payments to them.
So our Internet censorship started a few years ago with a very limited purpose and good intentions. And it was solemnly promised that nothing else than child pornography would be censored.
But once the infrastructure for censorship was in place, the censorship started spreading to other areas. And the censorship is getting more and more widespread.