The Federalist Papers were anonymous because of the fear of reprisals for the expression of political opinions. The anarchists are free to state their opinions openly, and they do so - but they wear masks to protect them in the commission of crimes, which is an entirely different matter.
I’d agree that there is a difference between wearing a mask and throwing a brick and wearing a mask and making a political speech, but anonymous speech has a long and important history in this country, and it deserves to be protected.