The Chinese authorities are staging a “man-in-the-middle” attack on Apple’s iCloud service in an attempt to steal username and password information, according to anti-censorship watchdog group GreatFire.org.
As per Wikipedia, a man-in-the-middle attack “is a form of active eavesdropping in which the attacker makes independent connections with the victims and relays messages between them, making them believe that they are talking directly to each other over a private connection, when in fact the entire conversation is controlled by the attacker.”
GreatFire.org first noticed the apparent attack when it became aware of the fact that certain connections made to Apple’s iCloud site in China no longer responded with a trusted digital certificate, thereby risking decryption.