Yes, it's down because of yet ANOTHER security breach:

http://www.heraldsun.com.au/technology/australia-post-hit-by-security-breach-again/story-fn5izo02-12...

My favourite part of the article is the bit where it says that  " the company did not believe people were smart enough to discover a flaw on its Click & Send service that was putting customers' privacy at risk."

How complimentary. 

This latest screw up makes me more and more disgruntled.  These things are so easily prevented with good IT security.  But I guess we don't deserve that . . . .