> In meat-space, the social norm is clear

Local social norm, in your meat-space neighborhood, sure. Also, norms from the other places, if you've did the research, or if their norms are close enough to what you're used to so your behavior is compliant or at least tolerable (for a foreigner).

Still, nerd social awkwardness issues aside, I tend to believe there there are quite different social norms in drastically different meatspace areas.

On the Internet it's only worse. You can't even tell which country/jurisdiction the site you plan to visit belongs to (no, addresses from whois may be a continent away from the legal system site ToS mentions). I neither think there are universal laws regarding this (to best of my knowledge, there aren't), nor that you can always know whenever it's legal to click that link you saw someone had posted on IRC or not, or read that link's contents, or save it.

(Ever thought that "liking" a post on a social network can be a criminal offense punishable with a few years in jail? In some countries it could be.)