Any way to disable custom text formatting?

Is there any way to disable custom text formatting in comments for all users on my end?  
 
There's one recent user in particular that has made his text about 5 times larger than normal and comments INCESSANTLY.  
 
Please tell me there's a way to disable it. 
 
It's driving me crazy!
 
 
 
:drooling:  :drooling:  :drooling:  :drooling:  :drooling: 
 
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