We are only a few hours into Winter Bash 2014, and already almost all the secret hats have been found and understood.
This is all very well, but it leads to a very rapid spike of posts and votes (not necessarily useful ones) to copy them. And this definitely causes annoyance to some folks (especially mods) as they try and minimise the mess to normal running of the site over the festive period.
As they are all explained at the end of Winter Bash anyway, I'd like to see more complex requirements for some - which would need you to show quite a few of the positive behaviours, not just one.
That way you would find it much more difficult to identify which action caused the hat to appear, and encourage activity (positive activity, if the behaviours rewarded are positive)
Also - it makes it more of a technical challenge/game/puzzle!