Bruce Schneier, a cryptographer, applauded Lavabit’s decision, pointing out that its self-destruction was made possible because it had no shareholders to answer to. “Could you imagine what would happen if Mark Zuckerberg or Larry Page decided to shut down Facebook or Google rather than answer National Security Letters? They couldn’t. They would be fired,” Mr. Schneier wrote on his blog. “When the small companies can no longer operate, it’s another step in the consolidation of the surveillance society.”