What should I do in this situation?

[amantra]

Few days back my brother went back to the city where he works. He was here at home with us for a week, and had a good time. Later I found out that he had left his Facebook profile open in one of the fr apps in my IPad. I ignored it for a few days, then I thought I'd play a prank on a few of his friends by messaging them. When I opened it, I saw in one of his messages to his friends my name cropping up. Out of curiosity, I opened it( sorry I know I shouldn't have), and there I saw he wrote so much bullshit about me to his friend!!( a girl). He wrote I feel like slapping my sister, she's good for nothing, and that's why he's not talking to me. I was like wtf?? We didn't even fight before we left, and what nonsense was he spouting?? Plus he exaggerated about my father being in the hospital, and he had to come back to the city again, and how he had to multitask between work and caring for my father. Whereas the truth is he just had a minor throat infection, he wasn't hospitalised, and my brother wasn't even in the city!! Such nonsense!! He was just gaining sympathy!!

I'm thoroughly shocked that he used me as such an excuse, when I didn't even do anything to him. What should I do about this??