User blog comment:Ninjinian/The Club Penguin Beta Crisis of 2010/@comment-938423-20100502101016

The full story thanks to Matre10 from TCPC:

On May 1, 2010 - a hacker was able to get into a Club Penguin moderator server that the staff forgot to make private. This enabled him to create a trainer which would allow you to get almost all the items on Club Penguin ever, excluding some and including the 413 (Beta Hat)

A lot of penguins that have hacked the items were banned forever or had their beta hat removed. Club Penguin fixed the error in their database allowing the hacker to give away free beta hats, and everything is back to normal right now.