“Busting a nut” means working very hard. “Bust” also means a police arrest, and “nut” also means a crazy person. “When cops catch a crazy person, that’s called ‘busting a nut’” was posted on Twitter on May 20, 2013.
 
“What do you call it when a cop arrests an insane criminal? Busting a Nut” was posted on Twitter on April 10, 2016. “When police arrest a mentally unstable person, technically that qualifies as busting a nut” was posted on Twitter on November 9, 2017. “When cops arrest a clinically insane person are they busting a nut?” was posted on Reddit—Jokes on February 6, 2018.
 
“If an officer arrests an insane man, is he busting a nut?” has been printed on an image.
 
   
Wiktionary: bust a nut
Verb
bust a nut (third-person singular simple present busts a nut, present participle busting a nut, simple past and past participle busted a nut)
1. (idiomatic, slang, vulgar) To ejaculate.
2. (idiomatic, slang, vulgar) to work very hard, put in a lot of effort
     
Twitter
Nate Fernald‏
@natefernald
When cops catch a crazy person, that’s called “busting a nut.”
12:20 PM - 20 May 2013
 
Twitter
Jameson‏
@jamesonfoulke
“What do you call it when a cop arrests an insane criminal?
Busting a Nut”
-@doctorwatermelo
7:35 PM - 10 Apr 2016
   
Twitter
McLovin‏
@lort_byron
What do you call it when a cop catches a crazy person
Bust a nut
4:57 PM - 14 Apr 2017 from Washington, USA
 
Twitter
Jeremy White‏
@comicref
When police arrest a mentally unstable person, technically that qualifies as busting a nut.
11:25 AM - 9 Nov 2017
 
Twitter
ten cents‏
@CarderCasper
If a police officer arrests a lunatic…
Is he busting a nut???🤔🤔🤔
11:29 AM - 22 Nov 2017
         
Twitter
j a n e s s a‏
@janessaharris_
If a police officer is arresting a crazy man, is he busting a nut?
10:48 PM - 25 Nov 2017
 
Reddit—Jokes
When cops arrest a clinically insane person…
submitted February 6, 2018 by Thezperk
...are they busting a nut?
 
Twitter
Nick Keimig‏
@Nick_Keimig
When cops arrest someone who is critically insane, are they busting a nut?
12:20 AM - 6 Feb 2018
 
Twitter
Best of Reddit‏
@BestoReddit
When cops arrest a clinically insane person… : ...are they busting a nut?
1:06 AM - 6 Feb 2018

Twitter
LaffGaff‏
@LaffGaff
When cops arrest a clinically insane person…
Are they busting a nut?
#funny #jokes #jokeoftheday
4:12 PM - 18 Feb 2018