Hyperbole, much?
First, bank accounts weren't frozen willy-nilly. The accounts belonged to those who were organizers, the truckers themselves, and those who contributed significant funds (if you donated $20, you weren't looked at). Further, you were only hit if you made donations after February 15th.
Second, only about 200 accounts were frozen as of February 17th, and by February 22nd, most of those had been unfrozen.
Third, the actual number of individuals was less than 200, given that some people had multiple accounts frozen.
Fourth, not all those people actually lost access to their "living money"; some accounts that were frozen were people's second or third accounts or accounts set up specifically for the protest.
Finally, other than (I'm assuming) the organizers, actual protestors could have avoided having their accounts frozen by simply leaving before this all kicked off. Further, almost as soon as they did start leaving, their bank accounts were unfrozen.
No one was stranded; no one starved.
Not a sledge hammer. It actually sounds like a very reasonable and proportionate application of the financially aimed capability.