Funbobby,   Even with the most tyrannical government, natual law cannot be avoided. Like Locke pointed out, oppression causes revolution, without it there would be no reason to overthrow a system. Again, by denying someone their rights the course of events dictate eventually that the perpetrator has forfeited their own right. A good example that comes to mind is the assassination of Julius Caesar. When he began defying natural rights and became a dictator the responce from the Senate was the course that followed. 

Natural rights such as the right to self defense is not made valid by the 2nd ammendment. The entire bill of rights was a compromise. Because people such as Patrick Henry and other anti-federalists were losing the debate at the time, and the populace was moving towards a central government, they found allies in trying to uphold natural rights within the Constitution, and presto they codified them. Natural Rights preexist any document or government. If rights were dictated by governments as your arguements suggest, than Stalin was perfectly in his rights to starve to death millions in Ukraine. That arguement is madness.