It seems that the Nevada State Athletic Commission is stepping up their efforts to "randomly" test MMA fighters. This time around it was the fighters that were in Las Vegas for the UFC 146 press conference: UFC heavyweight champion Junior dos Santos, Alistair Overeem, Cain Velasquez, Frank Mir, Roy Nelson, and Antonio Silva. Ron Kruck of Inside MMA/HD Net tweeted about it a little while ago:
It makes sense to test them at this point in time since they are all in Nevada anyway, and putting them all through the wringer at once means that they look as impartial as possible. If you read between the lines a bit though, Alistair Overeem had some issues with testing for his last Nevada bout at UFC 141, and was convicted of misdemeanor assault today in a Clark County courtroom. He also owes the commission two random tests as a condition of his conditional license, so it shouldn't come as much of a "surprise".