Fair points. #1. I still think #2 is a more important barrier, but I don't see a huge downside with this either. You didn't explicitly say this, but I think yo

Fair points. #1. I still think #2 is a more important barrier, but I don't see a huge downside with this either. You didn't explicitly say this, but I think you're making the point that troll accounts can never be completely eradicated. But you can make it significantly less convenient for them, while minimally inconveniencing most legitimate users. #3. I get the general idea, but I don't see how it's substantially more secure than requiring 2FA. I mean, GMail, Dropbox, AWS, etc., seem to think 2FA is sufficiently secure for very sensitive data, and they allow interacting through the web browser. Plus, at the end of the day, you'll need some mechanism for adding new devices, which will effectively work like 2FA – I presume.