Jennings was critical of Smith's brother Chris in a tweet, to which Smith responded by apparently threatening him, saying, "Might call some of my Number street homies an put #Detroit on smash for a min! #DeadSerious."
Smith later deleted that tweet.
(The irony is, in one of the many tweets Smith sent calling out Jennings, he said, "No respect for these lil kids who pop at the mouth on twitter an then want to delete they tweets! #GrowUp! #ManUp! @TheOnlyCSmith0 #Facts!")
Eight players have now been fined for an incident on Twitter since 2009, with Smith and Amar'e Stoudemire being the only two players to have been fined twice. Matt Barnes was fined $25,000 for inappropriate language on Twitter on Thursday.