A common word used by 50 Cents arch rival The Game. It refers to the tragic things that happened in 2008 (ex. A suicide bombing occurs in Zayouna, Baghdad, killing over 250 people during a funeral over the deaths from the preceding attack.) Saying to someone that you're 2008tin' on them means that you're doing something bad to them or something bad is happening to them.
(Lyrics from Big Dreams by The Game.) The whole world been waitin' on him. Here I come, droptop Phantom. I'm skatin' on 'em, look around. All the bitch niggas hatin' on him. Mad cos I'm Chronic 2008tin' on them.