@Vincenzo -- the legal system is doing something about malicious prosecution. The primary instrument used is the code of ethics in various states that punish those attorneys involved in malicious prosecution. The theory seems to be that attorneys are often co-conspirators, at the very least, in malicious actions. If the lawyers are punished, they will be less likely to bring those actions.
That is a theory, of course, and we don't yet know how sound it is.