In the US, the Secret Service are knocking on peoples' doors over things they post on social media.
This is terrifying stuff which would never happen in a free country, and was unimaginable in the US 100 years ago.
But I might offer a little bit of advice :
1. Live somewhere where there's a decent sheriff (if you can)
2. Get to know your sheriff
3. If goons come to your door, CALL HIM
4. Either real-name post (like me) or be really good at opsec, because these people are pretty good at doxing and will use what you say against you.