Tor Browser: How do we help users to use higher security?
The security slider lets users adjust their Tor Browser's behavior along the security-usability tradeoff. But Tor Browser is a juicy target, so we'd like to encourage users to use Medium-High Security or higher. But right now we set the default to Low because we don't want to scare away naive users who would think that Tor Browser is "broken" at higher security levels (when JavaScript and other features are disabled).
So an interesting UX question is how to design an interface that helps more users choose higher security, without driving users away. Testing would be important, I think.