I'm chairing a UNESCO committee on how to improve global Internet communications for science; help third-world people get onto the Net so they can be part of the process.
If we have isolated individuals able to inflict enormous harm, imagine what a single lunatic can do with a nuclear weapon. I think the whole base of civil society is at risk.
If you want to solve very complex problems, you will have to end up letting machines work out a lot of the details for themselves, and in ways that we don't understand what they are doing.
When I was in high school, I became interested in cytochemistry: chemical analysis under the microscope, and trying to understand the composition of cells.