Gun enthusiasts in the US often claim that it's important that citizens can bear arms in order to protect against a government that has become tyrannical. However, I don't think that argument really holds water - it seems to me to be a rather outlandish fantasy that a group of citizens could overthrow the government.
For a tyrannical government to have any effect, the power structures between it and the people would still have to be largely in place - in particular, the military and the police would have to be still taking orders from the government. But any given individual citizen gun-owner would be vastly outgunned by the military, which has access to far more powerful weapons. So an extremely large number of individual gun owners would be needed. I have no idea how many, but it would probably have to be several times the size of the US standing army, so in the multiple millions. But if the government failed to convince all those millions of people that it is not a tyranny, how could it have convinced the military and the police?
A far more useful tool against tyranny is an educated and well-informed population. If you can't pull the wool over the eyes of the people, you also can't pull the wool over the eyes of the agencies enforcing the will of the government. For this reason it's far more important that people get accurate and unbiased news than it is that guns are kept legal. If a tyrannical government does emerge (and there are some indications that it already has) it will be because the people have been lied to, not because they don't have enough guns. And frankly, the state of most mainstream news is so bad that this does seem to be a real danger.
It's very important that we all have a good understanding of current affairs. To do this we should:
- Avoid getting our news from just one source, or from sources with similar bias.
- Check the facts - follow up on the references and follow the chains of evidence back to the source wherever possible.
- Know our fallacies
- Disregard news sources that rely on unsubstantiated rumour ("Some say that...")
- Be particularly wary of religious arguments, since in religion not only is objective evidence lacking, but searching for it is actively discouraged.