... Obama would like to restrict guns, but can't, because they are too popular (in the USA).

... Governments tolerate this sort of abuse [black markets] only because they believe, I think correctly, that Bitcoin can have great benefits for their ordinary voters and for now are willing to let the tech industry experiment.

Those two reasons must be recognized for their differences.  What does it mean that something is "too popular" if the ultimate goal of government is "great benefits for their ordinary voters"?  It means the government assumes that some things are bad for people even though they are popular.  Crystal meth and heroin come to mind.  This is a natural concern of all decent parents for their children, and the reason that cultures for millennia have had rites of passage, wherein the child takes on the responsibility of determining for him or her self whether or not a popular thing provides great benefits.  That responsibility is the birthright of every human being. Why is there an institution that usurps it?  How do the people within that institution benefit from being part of it?

Some history to study and answer these questions includes:

• The origination of public schooling as motivated by Johann Fichte's public letters to his king in response to Prussia's loss to Napolean at Jena.
• Franz Oppenheimer's book, The State, tracing the origination of the idea of a state, or group of people who make up and enforce laws.
• Carroll Quigley's history book, Tragedy and Hope.
• Larken Rose's book, Kicking the Dragon.
• The Republic, by Plato, but only once you understand those other books.
• If you want a shortcut, John Taylor Gatto did a five-hour interview which is now titled "The Ultimate History Lesson with John Taylor Gatto."  It is heavily sourced by its producer in case anyone wants to verify the information he provides.
  

I'm "notplato" for a reason.

notplato