The NET Act of 1997 allows criminal prosecution of copyright infringment even when there is no monetary gain and has maximum penalties including up to five years in prison and up to $250,000 in fines, none of this including statutory damages which can get ridiculously high.
While SE probably wouldnt go as far as the maximum charges, the fines and damages cost would be more than a few fans would be able to pay without significant debt and filing for bakruptcy.
the team even had plans at one point to make this into a full remake which if distributed would probably had allowed SE to hit them with maximum charges.