As a lifetime bicycle commuter with over a quarter million miles on my drivetrain(s), and having put plates on my bike myself as an experiment, I can tell you putting license plates on bicycles is an almost completely useless and wasteful government activity. Any city requiring bike plates is doing so to mainly just to discourage cycling, not for any real liability or safety issue.
Point is there are two facets of this. Besides the obvious privacy concerns of data retention and efforts to limit abuse in that arena, there's also a whole world of pre-emptive evasion on the other side of the coin. Even if plates are on bicycles, nobody really cares about them, bothers to track them, or profiles riders.
One difference between the two is that I have immediate control and ability to implement the latter, whereas I would have to rely on others, resources far greater than my own, and a questionable legal system, to implement the former (and in the meantime I'm still playing their game, and obviously losing).
Simply avoiding driving cars isn't exactly anarchy, but it effectively leans that way.