A common question I get from people disturbed by these kinds of cases is, "What can we do?" Well, here's one thing the average citizen can do: Serve when you're called to jury duty, and while there, refuse to enforce unjust laws. If a defendant is guilty of harming someone else, certainly, throw the book at him. But if he's guilty of violating a bad law, or if you feel the law has been unjustly applied to him, by all means, come back with "not guilty," no matter what the judge, the prosecutor, or the evidence says.
Not only is this your right as a juror, some would say it's your obligation.