I was reading DeepDotWeb and there was news a pedophile nubcake, little technical details were in it, however in the article there was the signs of someone who is absolutely finished. Files were recovered from one hard drive and as the article says there is a good chance they will find videos on a second drive. In this sort of situation someone could simply not hand over their passwords. However, that could open someone up to obstruction of justice.
There has to be evidence for a charge of obstruction of justice, in this case there was through bad OPSEC or slopsec of the pedophile. However another pedophile got away with allegedly possessing child pornography because his lawyers demanded the exploit itself be submitted to the court and thus the public eye, as you can read in this Wired article. Without that evidence they could not prove there was anything protected by cryptography of his hard drives.
It is said by many that cryptography doesn't matter except to protect you against hackers and governments have the rubber hose. While they do, if you live in a country with due process where you are innocent until proven guilty in a court of law proper OPSEC can save your cryptography. Its simply very important to not leave a trail, use a secure system, and not make identifying mistakes. There is a defense against the rubber hose of obstruction of justice: you must assert that there is no evidence you are hiding anything, and demand they respect your privacy.
You have to realize there is a distinct difference between paranoia and actual security. If you are paranoid and fear the government and the courts too much you might cave in when you really don't need to. Keep a cool head and consider the chain of evidence leading to your systems. However, it is possible they will withhold evidence without your lawyers knowing which later proves the obstruction of justice charges. Prosecutors and surprise evidence is nothing new.
There is also the old tale of Al Capone getting done for tax evasion. There are many laws and many illegal things that they might use against you. My favorite thinker Ayn Rand and many others like to call it selective enforcement of the law. They might not be able to prove your server hosts a drug market with circumstantial evidence from an exploit they are unwilling to reveal. However there are other circumstances which could lead to criminal charges, such as tax issues, crypto-currency analysis and such which could reveal you are breaking other laws.
This means you should put a lot of thought into your life when you're unplugged. Keeping a low profile isn't everything, when it means you look like a man who makes something from nothing with chainanalysis, banking records, and how much money you spend behind time. Make some investments when you get bigger, open a cafe, donate to charity, and keep yourself busy. Russ Ulbricht was a very rich man sitting in a socialist library, don't be that guy. It would be better to be sitting at the CEOs desk on a company selling information technology, or a small back office in a pizzeria.