Given the power assymetry, hugely favourable to Spain, the only chance for Catalonian independence is to get external support that will twist Spain's arm. Here is where they are concentrating their efforts. They are trying this on many fronts, some legal (EU court in Strasbourg), but mostly by trying to keep the conflict in the front page of international media. This has worked partially (by damaging Spain's image abroad), but are still very far from their goals (UN resolution against Spain, EU warning, a big state or leader putting this on their agenda). Part of this is to commit illegal but not quite criminal acts, followed by an outcry and demonstrations when they invariably get banned by Spain. This "digital republic" is just one of many such acts. Spain is actually reacting with enormous restraint, given the propaganda disaster of past mistakes like the riot police during the illegal referendum.
Unless forced by the international community, Spain will never allow Catalonian independence, no matter how bad the internal situation, in my opinion. This is a matter of national interest for Spain, an existential threat, because it is one of the largest and richest regions, and because others would follow (at least the Basques), and Spain would just cease to exist.
Democracy is crucial, but, as with all complex problems, there are trade-offs to be made, one can't aim for absolute democracy at the expense of everything else, we should be careful with absolutes because they are not realistic. This is not a matter of human rights, or Spain being a fascist state, franquist, or a dictatorship. Spain has never been accused by other EU countries of being undemocratic or not respecting human rights (or, at least, not worse than other nations like France or USA).