Today while using Flickr, instead of returning a normal response page to me, it dumped a giant data structure to the screen instead. It appeared to be nearly complete set of all the details it stores about me internally. Some details were not all that surprising, like:

'stats_cluster_id' => '3',

That would indicate that they have multiple clusters of computers that serve their statistics, and when I access my stats, I'm talking to the third cluster of computers.

A few bits of data were especially intriguing. The appeared near the bottom of the list, which is perhaps an indication that they were added more recently:

'is_nazi' => 0,
'vitality_opt_in' => 0,
'has_used_beehive' => 0,

Now, what would Flickr be using the "is_nazi" flag for? As for "Vitality" and "Beehive", perhaps these are new feature or services that are not public yet.