And, relatedly.... if I offer to perform allegedly-medically-beneficial surgery for free, am I exempt from all the laws about regulation of medical practice?

And relatedly, if I give away viruses for free, am I good to go?

Not that I'm particularly sanguine about the odds of legislators getting it right, but I agree with rayiner that "open-source" isn't a GOOJF card.

On the other hand, it seems clear that code I write only for my own use has different regulatory requirements. In general, laws often let people do riskier things for themselves, relative to risks they let people take on behalf of others. But in this case, if you write code for yourself, it's obvious that you opted in to its features.