Getting back into modding...

So I use to mod MW2 in like 2011-2012, and obviously I got banned within the next few days. But, i've been seeing a TON of hackers in public lobbies, one of them said they were already VAC banned, now how is he still modding online if he's VAC banned? Anyone willing to give me some pointers so i can start modding again, Thanks! (I know all the basics)

you need mw2 liberation go bypass vac ban and then you force host and it should byypass vac