This version of "Santa Claus is Coming to Town" is said to have been sung at a Carter Administration Justice Department Christmas party sometime in the late 1970's. 

Enjoy.

You’d better watch out,
You’d better not cry,
You’d better not pout;
I’m telling you why.
Santa Claus is tapping
Your phone.

He’s bugging your room,
He’s reading your mail,
He’s keeping a file
And running a tail.
Santa Claus is tapping
Your phone.

He hears you in the bedroom,
Surveills you out of doors,
And if that doesn’t get the goods,
Then he’ll use provocateurs.

So–you mustn’t assume
That you are secure.
On Christmas Eve
He’ll kick in your door.
Santa Claus is tapping
Your phone.

H/T: Eugene Volokh @ The Volokh Conspiracy