"[A]s the term is generally understood, the practice of the law is the doing and performing services in a court of justice in any matter depending therein through its various stages and in conformity with the adopted rules of procedure. But in a larger sense it includes legal advice and counsel and the preparation of legal instruments and contracts by which legal rights are secured although such matter may or may not be depending in a court of law." (People v. Merchants Protective Corp. (1922) 189 Cal. 31, 535, quoting Eley v. Miller (1893) 7 Ind. App. 529 [emphasis added]).
Here's some unauthorized legal advice for ya: Posting your opinion on random legal matters on HN has about 0.00000000000000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000000001%
probability of every resulting in any legal backlash for the commenter. And in a country which is supposed to cherish free speech as a principle, we should absolutely all feel good about giving our opinions, and if the courts have a problem with that, telling the courts to go fuck themselves.
Someone on the Internet explaining how to file for divorce, bankruptcy, or commenting about legal issues related to a startup seems outside of the scope of "unauthorized practice of law".
Does this mean legal advice on the Internet is good advice? No. But I think it's far from illegal unless someone claims to be a lawyer & accepts fees for services.
But now I am probably going to jail thanks to expressing an opinion on how I viewed the law you quoted.