Now, if the TSA rules are legally binding, aren't they essentially asking about breaking the law?
Well, maybe. But if you're unsure as to whether or not those rules are legally-binding, much less whether or not they're actually asking how to break them, then chances are they're in the same boat. Closing it doesn't really accomplish anything here, apart from sending someone with a (constructive, probably on-topic) question away empty handed.
If it's illegal, then that's an answer. There should be plenty of sources that can be referenced in this case.
If it's just a bad idea, then an answer explaining why could potentially save someone a lot of headaches.
If it's legitimately possible (even if only in specific circumstances) then that would be very nice to know as well... And again, someone should be able to cite official sources here.
When in doubt, err on the side of helping people, not shutting them down just because their question makes you uncomfortable. And remember, "don't do it" is a valid answer - as long as you explain why.
Note that there are plenty of reasons why your community may decide that they don't want to be involved in answering questions on certain topics, including concerns about projecting an image of lawlessness. This is a decision that should be made by your constituents on your meta.
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