> What prevents a malicious actor from buying and using these tools?
Nothing.
What prevents any actor from buying <insert any items here> and using it maliciously? A significantly deeper question. I rather promote this.
I do not think there is a simple answer, but there is one out there...
When you can pick every lock around you it changes your worldview forever.
Kids should not avoid something wrong because they are physically stopped by a lock.
They should avoid it because it is wrong.
Better they learn these skills from someone that will teach the ethics to go with them.
I am surprised that selling tools which potentially "enable murder" hasn't triggered some overzealous regulator in DC yet. It seems like low-hanging fruit. /s
Pro-authoritarian sentiment keeps going strong. Why is it so normalized these days?
If you asked a reasonable person off the streets why bioweapons (like anthrax) should not be easily purchasable, they would completely agree and hence the legislature has made such things illegal.
But if you asked that same reasonable person off the street about miniature computers and electronic devices, they would probably not imagine that such uses are possible, nor would they deem it dangerous. They might even consider it useful! So legislation on such things cannot be set by societal expectations.