My, my. You have no clue how the real world works do you? In your scenario, anyone who has ever been accused of a crime has had their constitutional rights violated. FYI: You and I can be accused by anonymous police informants and we don't have the right to cross-examine them. Also, what happens when an anonymous citizen comes forward to make the accusation that a heinous crime has been committed? Do the police ignore that anonymous intelligence? Or do they check into it and if there is probable cause to believe a crime occurred, investigate it. If there is independent evidence a crime occurred, should the case fail because the anonymous caller is, in fact, anonymous and thus cannot be confronted in court?  I think you need to read up on criminal procedure and evidence.