I want REVENGE on my EX, but will this get me in trouble?

No you can't get in trouble, unless you did something actually illegal. I'm uming you wern't wiretapping his phone and opening his mail (real paper mail). But you should just let it go, if you know he isn't right for you just move on. Holding a grugde and pissing him off won't really help you on your path to the right person. BTW 31% best answer thats impressive.