The said video was uploaded by a Facebook page entitled Duterte and Bato Supporters, a page where obviously the admins are Duterte supporters has tagged Sen. De Lima singing classic song inside the National Bilibid Prison.
Many netizens were tricked by the said video, believing it was really De Lima singing the George Michael hit Careless Whisper inside the prison. But there are some who noticed that it was elsewhere and not inside the prison cell.
It has been confirmed by the Summit Express that the senator was a guest of honor during an event where she attended and not the National Bilibid Prison as many thought.
Source: Duterte And Bato Supporters / Facebook