That's you showing yourself off, outside your own property. And note, there are times this is legal too, such as when a man stripped in an airport to protest the TSA.
You know full well that indecency laws apply to broadcasts, signage, and other displays, including displays on your own property if there's any expectation anybody can see it from off the property. Quit trying to use pedantic tricks.
No, it's governments using those externalities as a smokescreen to go down the slope on purpose. I just gave two examples, and I didn't mention gun control or censorship at all here?
But sure, let's use gun control: The entire history of gun control up until the mid 2000s. A slippery slops of promised safety used to rob freedoms.
Or censorship. Banning harmful words in the UK eventually lead to arresting people praying silently. Not quite censorship, but the government (notably the FBI) uses the excuse of needing to investigate crime such as child porn to campaign and sue anyone offering strong encryption, to try to get them to break it. And I want laws against child porn, I'm just well aware the government will try to use them to expand its reach.
Yes, that was my error, I misread your putting the phrase "Put a gun to their heads" as a gun control message.
The two examples you did give, parenting and the government claiming distrust of government is an externality.
For the first, there's no connection between externalities and parenting. Abusive parenting causes direct harm, it has no externality involved. Non-abusive parenting causes no harm, it has no externality involved.
For the second, words have meanings. Given how pedantic you are I'm surprised you'd miss that.
Gun control does have externalities involved and most reasonable gun control advocates understand and accept it. That's why, f'rex, most gun control advocates are in favor of gun owners using safes and responsible storage, and why all but the most fanatic 2A supporters do not support rando civilians owning explosives or nuclear weapons because they have a 100% chance of blowing up bystanders if used in self-defense. That externality matters.
No, they really aren't. Because most externalities are willingly taken up, including this one, so it is no harm. The only externalities that matter to a Libertarian are those that aren't consensually taken up, such as pollution.
Basically, you can leave someone to starve on the street. You choosing not to do so does not mean you were harmed.
And that is why you fail. Not bothering to take basic human nature into account guarantees your system of ideals will not work in real life.
You can leave someone to die in the street... but you will create negative externalities for the whole community. First the starving person is likely to spread disease as they sicken. Second, they'll become a nuisance in the public square. If they die in the street, well
somebody's going to have to pay to clean up that corpse and bury them.
Of course, it won't come to that, because nobody actually follows libertarian ideals and the starving person is going to turn to crime to survive, which will further cause harm to external people and the community.
And of course, the reason most externalities are willingly taken up these days is because we
regulate the hell out of externalities. We don't have factory workers getting phossy jaw because the government came down on the unsafe practices that caused it like the fist of an angry god, but it happened for decades before that and years of citizens trying to come up with market-based solutions failed utterly. We don't have utter bullshit like the Triangle Shirtwaist Company* anymore because of regulations stopping it, not because human nature would prevent another Triangle Shirtwaist, otherwise it wouldn't have happened the first time. Remove those regulations and the externalities will be forced upon the citizenry again. We don't have buildings routinely collapsing and killing people or massive fires like the one that ate Chicago in 1871 because of building codes and regulations, but we did have that happening all the time before those regulations existed.
This can actually be solved via property rights, by assigning each lot of the river a tradeable right to decrease flow by some %, etc. Not fatal to libertarianism at all. There's more specifics here, but it works similarly-ish to how a state can sue another state for using too much water, but on an individual basis. Combine that with the ability to buy and sell legal harms, and you've got a business going that sues people for overusing water. And initial hand out of % would be based on what % was historically used, as per Locke's understanding of creating property by combining nature with labor, they then own that % of flow. Or maybe don't use % but absolute flow rate.
And who is going to assign these lots and regulate them? Sounds like a big government to me.
And to toy with your slippery-slope all-the-way-to-one-side-slider fallacies, why won't they apply this system to everything else? Assign lots to people for how high and what shape they can build their homes, because it could cast a shadow on their neighbor's yard and reduce the sunlight available (Note this isn't purely hypothetical, Japan actually needs laws for this due to how closely buildings are spaced). Assign lots for how much air pollution you can cause. Hey, why not assign lots for how many children a person is permitted to have? After all, having too many kids risks causing harm by them not being able to feed them all, so logically only the really wealthy should be able to have as many children as they want. The public roads, well those are maintained at the taxpayer expense, and the atmosphere we breath is supported by plants, which are crushed when people walk on them, so let's assign lots as to how much walking and driving a person is allowed to do each week, and enforce that every person must grow maintain a specific amount of plants that will offset their carbon production.
And then at the end... you've made a government bigger and more intrusive than the one you're railing against.
