Ok you're going to a protest. If you're suddenly unjustly targeted by cops/government agents, what's your plan gonna be? Where will you go to hide and lay low for awhile?

Now is the time to set up a net of safehouses for: holding planning sessions, storing supplies, training, and to hide those escaping after successfully protesting the government and the law is on their tail.

Their defence is that they are kept secret because their safety does not rely on police protection: the occupants provide its only protection from adversaries.