Neville those wanted posters are for things your parents did years ago. YEARS ago. Back when they were the Aurors and Barty Crouch and Bellatrix Lestrange were the fugitives on the other side of the law.

And Draco's right, if it's a spell that's used to kill people that's 'Dark Arts,' those are 'Dark Spells,' I mean your Mum messed up Rabastan Lestrange so badly he still limps, that wasn't Stupefy or Petrificus Totallis or Expelliarmus they hit him with, they were hitting him with something that could kill him. (Not Avada Kedavra obviously or he'd be dead. But whatever spell they used, it's not going to be taught in Defence. It's not going to be taught in Charms. It's going to be taught in Dark Arts, or not at all.)