If a person is constantly being followed every where they go day and night isn't this a violation of privacy?
Not if in public. Otherwise, do you REALLY mean day and night? Unless you really are a person of intense governmental interest for reasons beyond those this forum can address, that you think anyone would spend the resources to do so (Or, that it is actually happening.) is an indication of paranoia. That is why Zigner suggested therapy.
Say a person is constantly being lied on and the lies are being spread throughout their immediate community and beyond ex: (he's a thief or a terrorist etc). Couldn't this be considered a violation and if so how would someone go about solving this situation as far as finding out who,what,when,where and WHY?
This could be defamation if untrue. You find out who by asking those who are being told, or, if CONSTANT you just listen for when someone says it. Then you file a lawsuit and try to get the other answers in discovery.
But, again, this seems more paranoid then real. Sorry, but, even if there is some basis in reality for what you write, it seems like a good first step is to talk to a mental health professional to help clarify your next steps.