Good luck with that in many developed countries [1][2], or in developing ones [3].
So many things are illegal that it becomes more a question of "do the powers that be wish me imprisoned?" more than anything else.
1: https://blogs.loc.gov/law/2013/03/frequent-reference-questio...
2: https://www.quora.com/How-many-laws-are-there-in-England-and...
3: This article
Er, how? Again, there are tons of laws on the books. Are you going to memorize them all?
Further, some of the laws are incredibly vague. For example, did you know that it is arguably illegal to boycott a business in Thailand?
> Section 117 Whoever, instigates or causes a strike, lockout, or concerted cessation of trade or business with any person for the purpose of bringing about any change in the Laws of the Country, coercing the Government or intimidating the public, shall be punished with imprisonment not exceeding seven years or fine not exceeding fourteen thousand Baht, or both.
> Whoever, with the knowledge of the above purpose, takes part or assists in the said strike, lock-out, or concerted cessation of trade or business with any person shall be punished with imprisonment not exceeding three years or fine not exceeding six thousand Baht, or both.
Are you assisting in a "concerted cessation of business" by actively avoiding an establishment you don't agree with? Are you guilty of "taking part" by liking a Facebook post from a group of workers on strike?
Maybe!
Sure, it's unlikely you'd be prosecuted. But as the article shows, it's always an option if they don't like you or need a sacrificial lamb!
There are times for civil disobedience, but one should not be reckless. You have to weigh the effect that you can have against the cost that you will pay. Courage is a strange thing. Sometimes it requires courage to act. Sometimes it requires courage to stay silent and wait for the right opportunity. It is rarely a straightforward thing, unfortunately.
I hope things go as well as possible for him.