“These days govt. is a four-letter word” means that “govt.” (government) can be obscene. “These govt. is a four letter word” (the word “days” appears to be missing) was on an Internet list of humor in 1994. The saying has been put on T-shirts and was briefly popular again on the Internet in September 2011.
 
   
Wikipedia: Four-letter word
The phrase four-letter word refers to a set of English-language words written with four letters which are considered profane, including common popular or slang terms for excretory functions, sexual activity and genitalia, and (depending on the listener/reader) sometimes also certain terms relating to Hell and damnation when used outside their original religious context, and/or slurs. The “four-letter” claim refers to the fact that a large number of English “swear words” are incidentally four-character monosyllables. This euphemism came into use during the first half of the twentieth century.
 
Common four-letter words (in this sense) that are widely considered vulgar or offensive to a notable degree include: cunt, fuck (and regional variants such as feck, fick and foak), jism (or gism), jizz, piss, shit, twat and tits.
 
The Humor List 
Date:      Sun, 14 Aug 1994 16:35:43 GMT+2
From:      Geoffolosophy Says:
Subject:    A note and graffiti

(...)
28> These govt. is a four letter word.
 
flickr
These days govt. is a four letter word.
By gmh. Graham Hicks+ Add Contact
This photo was taken on July 17, 2005 using a Nikon D50.
     
Serial Bus
Small Change for India’s Piggy-bank!!
Written by serialbus
September 21, 2008 at 8:44 pm
(...)
Long back, when I did not know what a four-letter word meant, I saw someone wearing a t-shirt that said ‘govt is a four-letter word’.
 
phpBB.net
These days govt. is a four letter word.
by codyevens on Wed Sep 07, 2011 1:25 am
Cloning is the sincerest form of flattery.
     
MyBB
codyevans
09-17-2011, 09:08 PM
These days govt. is a four letter word.