Yes they do. Do you really believe you're going to use your personal arsenal against the Federal Government if it decides to take some other right they agree with?
Guns aside I think the idea of personal sovereignty is an interesting one. It a concept that is almost completely lacking in the UK. We wrongly believe that people bodies and property are policed by social values and politeness. The greatest crime is not attacking someone's rights but breaking a taboo. This is very different to the American concept of individual liberty where people are actually allowed to be rude!
Guns no, but encryption yes. The right to "arms" includes encryption. Too bad the NRA sucks up the 2nd amendment discussion and casts it as only pertaining to guns.
Hoarding guns makes it easier for some people to sleep at night because they think that the government is going to come for them, or they are preparing for the fall of civilization.