I'm going to get back at my ex. He deserved everything coming to him.
What did he do to deserve it?
You already know what he did.
Wanted to get back at someone who wronged you is something I'm sure everyone thinks from time to time but that doesn't mean you should do it. Being rude or doing something inappropriate to someone, even if you think they deserve it is still wrong. Just try to move on instead and be a better person.
I guess it is a lot of work to get back at people and I could just chill instead.
That sounds like he best thing. You can surely be better off investing that energy in moving forward.