The "black market" arguments assume that the only source of oppression is from governments. The current reality is that a very significant amount of censorship and oppression is from entrenched corporate power. Some examples:
1) WikiLeaks suffered an economic blockade that was orchestrated illegally by Visa, MasterCard, Paypal and a host of major banks. There nothing "black market" about using Monero do an end run around an illegal corporate economic blockade.
2) Apple used DRM to censor the teachings of the Dali Lama, and has used DRM to censor all sorts of free speech. It used DRM to censor Bitcoin from 2009 - 2014 and is currently using DRM to censor Monero.
3) Amazon used DRM to censor George Orwell's 1984.
4) The MPAA and host of corporate interests tried to push the SOPA Internet censorship bill through the US Congress. When that failed they turned to waging a clandestine war against free speech and civil liberties on the Internet by attacking Google using Attorney Generals at the state level. The ultimate irony is that this attack on freedom and civil liberties was exposed as a result of the Sony server hacks. These hacks have been attributed to the Government of North Korea. The fact that even one of the most oppressive governments on the planet can strike such a worldwide blow for freedom and civil liberties illustrates the true evil in the MPAA.
I can continue but there are many "white market" products and services that are currently censored by entrenched corporate power to provide a major market for Moenro .