I'm worried about the Internet. Not about the usual Mozilla stuff, although there's a lot of challenges there too. I'm worried that the Internet, the way we use it, is bad for people; bad for individuals, and bad for society.
One reason is security. We do not have the technology to build systems with strong behavioral guarantees; there are always bugs, and always exploitable bugs. The contest between attack and defense is vastly asymmetric; defenders must get everything right, attackers only need to find a few mistakes. Yet we keep bringing more of our world online. Even keeping systems away from the Internet becomes infeasible as mobile Internet-connected devices become increasingly pervasive.
Another reason is our brains. It seems obvious to me that the Internet is a lousy medium for human interaction (beyond people you already know well). There are lots of negative effects at work, and better-informed people than I have much to say about them. "Filter bubbles" are one concern. The accessibility of support groups for every kind of dysfunction (e.g. pro-anorexia or racist groups) is another. My biggest worry is the lack of empathy we experience when interacting with others online. The online comments of almost any major public Web site are toxic, especially on controversies. I've behaved badly online in ways that I never would have in "real life". In the incoming direction, the core Mozilla community is great, but random abuse and conflict from the Internet takes its toll. There's a lot more to be said about what's going wrong, but suffice it to say I'm an optimist about different kinds of people being able to get along in real life; I'm a decided pessimist about them getting along online.
(Even while I'm writing this, Christian Heilmann has posted about problems on Twitter.)
Let's not even talk about privacy and oppressive actors.
I'm fed up with techno-optimists who claim the march of progress is inevitably beneficial and we're just having some teething problems. Techno-optimists had big dreams for the Internet; that it would bring people together (see people yell at each other on Twitter), that bad information would be cured by more good information (see filter bubbles), that all knowledge would be universally available (OK, they got something right; thanks for Wikipedia). Not good enough.
So what should we do? For security, we need to increase the distance between important systems and the Internet. We need to steer towards technologies with provable properties (and somehow escape our dependence on C/C++ code). But that's weak sauce and I don't see our way clear. Human factors will let us down and there are hard limits on technology.
The human interaction problem is even tougher. Maybe we can find technical solutions to reengaging empathy. Providing voice and video interaction everywhere might help; WebRTC could save the world! (Probably not, but we'll try.) Individuals can opt to reduce their online presence and refocus on offline relationships. To some extent that's what I try to do, and in a low-key way I'm discouraging my kids from being online and engaged with computers (mainly by giving them more interesting alternatives).
What about the mass of humanity? Do we just keep accelerating and hope everything works out? Do we form a neo-Luddite action group and sabotage the Internet? Do we figure out some alternative approaches to using the Internet that limit the damage? I wish I knew.