There has never been a time when I've expressed an opinion in my name and not regretted it later. Stay offline or anonymous. More importantly, stay clean
Free speech is required for people in a democracy to question their government, hold it accountable, and redirect it.
It's required for the free practice of science, religion and commerce, and anything else citizens might put their mind to.
If a government can suppress free speech and punish people for it, then we can't control our government.
That's the democratic argument. But more generally, unless I'm speaking to the government or committing an actual crime, it's none of their fucking business what I say or who I say it to. Governments are, or should be, formed to serve people, not the other way around.
If smart people pack their bags and leave, where are they going to go? To another country that may fall into despotism? At some point people have to make a stand. Free speech makes that stand less bloody.
