From the internets:
USAGE NOTE FOR THUG
The word thug has had racial and cultural overtones since its adoption into the English language. It entered English during the British colonial period to describe a particular gang of criminals in India, but from the beginning, the otherness of the Indian robbers was intrinsic to the narrative about British colonial victims.
In American English, the word is disproportionately applied to nonwhite perpetrators of violence or crime. White teens disturbing the peace at a party with loud music are more likely to be called troublemakers or hooligans. Their Black peers are more likely to be labeled thugs for the same offense. And following this common racialized usage, thug is used by some and interpreted by many as a code word for Black. In extreme cases, thug is chosen as a dog whistle to imply that Black people are generally prone to violence or criminality.
However, there is also a reclaimed sense of thugwithin the Black community, and particularly in the hip-hop community, one that acknowledges the violence implicit in the label while also celebrating toughness and street smarts.
Because thug has many implied connotations that may change depending on who is using the word and who is being described by it, it’s important to critically consider the context and tone around each particular instance of its use to truly understand what is being communicated.