If lots of people are pressured to deanonymize, which they are in this case (it's your civic duty!), that's not a very strong system because a lot can be inferred from "gaps" between people that you are linked to in other contexts.

Just like I can avoid using Facebook but they can still, in principle, keep a shadow profile with lots of details about my life, inferred by putting together knowledge from other people. Just like when I joined LinkedIn it already knew who I knew, without me entering anything except my name and email address (that was spooky, I didn't give it contacts or anything). Just like Google knows your personal interests, even if you delete all cookies at the end of every browsing session.

Are networks of social connections a characteristic that can be fingerprinted just like many other identifying traits (gait detection, location and movement fingerprinting, keystroke forencics, stylometry and linguistic fingerprinting, patterns of timestamps, et cetera)?