The fable of the "determined actor".

The "determined actor" can get bombs, tanks, fissure material. There noone says "WHELP they can get it anyway so why bother regulating it LMAO" - somehow this is different in anything not physical?

>Lots of countries impose exactly what specific regulations with respect to open source tooling?

that something is not currently regulated does not mean it can never be regulated, further it does not seem likely that they would regulate open source tooling but rather some uses and if they open source tooling allowed those uses then what would happen is -

github and other big sources of code would refuse to host it as containing not legally allowed things, so for example if they regulated it in the U.S then Github stops allowing it, and everyone moves to some European git provider.

At the same time bigger companies will stop using the library because liability.

Europe then regulates and can't be in European git repos.. at some point many devs abandon particular library because not worth it (I get it this is actually for the love of doing the illegal thing so they won't abandon but despite the power of love most things in this world do not actually run on it)

Can determined actors get ahold of them and do the things with them the law forbids them to do, sure! That's called crime. Then law enforcement catches determined actors and puts them in prison, that's called the real world!

Will criminals stop - nope because there is benefit to what they're doing. Maybe some will stop because they will think screw it I can make more money working for the man. And some will be caught sooner or later. And maybe in version two of the regulations there will be AI enhancements - this crime was committed with AI allowing us to take all your belongings and add 10 years to your sentence and deprive you of the right to ever own a computing device again...etc. etc. And some people will stop and others will get more violent and aggressive about their criminal business.

I don't know necessarily what measurable meaningful effect means, for some people it will be measurable and meaningful, for some not, for some of society the regulation would in many ways be worse than what it is fighting against. I'm not saying regulation will solve problems 100%, I'm just saying this whole they can't regulate us thing because "TECH!!!" that developers seem to regularly go through with anything they set their eye on is a pipe dream.