This was done so that people from neighboring municipalities who commute to Tallinn and would like to not pay for the public transport would register themselves as residents of Tallinn and the local municipality share of income taxes (roughly half iirc) would go to Tallinn instead of the others. The price for the 30 day pass was significantly raised as well.

In this light the taxes are redistributed, Tallinn local government has been incredibly corrupt (but strangely functional and with moves like this pretty bold and not dumb) and so one could argue that there has been more theft through corruption but that would assume that the neighboring municipalities are less corrupt, which is not exactly given.

As the goal is to entice people to register as Tallinn residents the tracking part of the plan is absolutely vital.

So in the end this is still a zero sum game or even net negative as it accelerates regional income and by extension brain drain.