Brugeaud steps in as tech chief.
Stolen data includes social security details.
Certificate bypass check possible.
Contract finally signed after months of negotiation.
Will increase 4G coverage to 2.5 million km2.
Tech executive musical chairs as two-year hiring freeze ends.
Makes "puzzling" $4.9m investment in calling card operator.
Cyber gang stealing sensitive info from big business.
Stock exchange down for three hours.
Writes down $10.2 billion on mobile acquisition.