Joseph Menn for Reuters:

A senior Apple Inc security expert left for a much lower-paying job at the American Civil Liberties Union this week, the latest sign of increasing activity on policy issues by Silicon Valley privacy specialists and other engineers.

Jon Callas, who led a team of hackers breaking into pre-release Apple products to test their security, started Monday in a two-year role as technology fellow at the ACLU. Prior to his latest stint at Apple, Callas designed an encryption system to protect data on Macs and co-founded communications companies Silent Circle, Blackphone and PGP Corp. […]

Callas said he felt particular kinship with Google employees pressing to have more of a say in the company’s prospective deal to return to mainland China with a censored search engine.

“A bunch of people have in fact woken up and said ‘Where are we, where are we going?’” Callas said. “These employees are wanting more discussion and access to what’s going on.”

Callas said phone makers had improved security and he wanted to see progress continue and widen without companies succumbing to pressure to install back doors.

There could be a simple explanation for his choice but the elephant in the room is Apple in China.