If the requirement to wear the tracking device is a part of their sentence, then it's not unconstitutional. Unless maybe some idiot judge ruled it was "cruel and unusual". If it's imposed on them after the fact, so to speak, then it likely is unconstitutional. That is, if people convicted before the law passed are required to wear the tracker. Sort of like the Domestic violence misdemeanor disqualification for keeping and bearing arms.
That law extended attainder to non-felonies. That's the bad part.