Noam Scheiber has a much-read piece at The New Republic positing that WikiLeaks "will be the death of big business and big government." In short, the thesis is that in the age of WikiLeaks, everyone is a potential leaker, and the larger the company or government agency, the more potential leakers it has. As tightening security is of limited effectiveness, there will be downward pressure on the size of organization so that they are:
Small enough to avoid wide-scale alienation, which clearly excludes big bureaucracies. Ideally, you'd want to stay small enough to preserve a sense of community, so that people's ties to one another and the leadership act as a powerful check against leaking. My gut says it's next to impossible to accomplish this with more than a few hundred people.
Even though Scheiber sidesteps a number of important factors pointing in the opposite direction, he echoes an important concept in the notion of social capital -- how reputation and influence works within a network. Networks in which everyone has strong connections with everyone else tend to have social cohesion that both reinforces community and monitors and punishes transgressions through coordinated mechanisms like gossip. As Ronald Burt points out in his writings on the topic, it's one thing if someone tells you something about someone else; it's another when you hear the story (or versions of it) from ten different people.
It's also true that, as Scheiber says, that social cohesion is highly sensitive to the size of the network. If a group has five people and a sixth joins, it's fairly easy for the newcomer to forge connections with everyone else. But when the sixtieth person joins, it's significantly more difficult. (The technical term for a group in which everyone has ties to everyone else is a clique; network scientists, realizing how difficult this is to maintain, will loosen the requirements a bit and talk of "near cliques" in which everyone knows almost everyone else.)
But if Scheiber's analysis reflects some important network truths, it also comes up short in a key respect. It's true that small, tightly-knit groups will have social controls against leaking. But the threat comes from the fact that most people belong to more than one group. And it's when relationships (that is, network links) cross from one group to another that leaking can occur. In fact, "leaking" is just a negative case of the more general phenomenon of information exchange between groups -- a phenomenon that we often look to encourage. As Mark Granovetter's classic paper, "The Strength of Weak Ties" described, you're more likely to find fruitful job leads not through your friends (who are likely to know about the same job openings you do) but through the friends of your friends, who probably are privy to different leads. Leaking works the same way. The people who are passing classified documents to WikiLeaks aren't publishing them themselves; they're (presumably) using the Internet to easily establish a link between one of their groups (for example, the State Department) and Julian Assange's clan. The social cohesion of small groups that Scheiber proposes may diminish that possibility somewhat, but will not remove it.