Your example is arguably a bug in human society.

But there's no doubt that the Internet increases the risk, given the massive scale, relative anonymity, cultural differences, and so on.

Hannu Rajaniemi imagines an intriguing solution in the Quantum Thief. In Martian society, aka the Oubliette, individuals cryptographically regulate who knows, and who can remember, what about each other. So everyone is fundamentally anonymous to everyone else, except for whatever they choose to share with another, or a group.

I can imagine something like Facebook or Twitter doing that, even using GnuPG.