I don't post my face, or tweet, or any of that nonsense. If my sister did that to me, I'd just do what I've always done to keep her in line since she was born: I'd sit on her head and fart, or give her an 'Indian rope burn'. Right in front of Mom. And my niece and nephew, just to see them giggle. I'm old school. I just deal with her accordingly when I come home for Christmas. And Big Bro always wins.
We'll be in our 80's, and I'll still be giving her a 'Wet Willie' just to push her buttons. 
"As democracy is perfected, the office represents, more and more closely, the inner soul of the people. We move toward a lofty ideal. On some great and glorious day the plain folks of the land will reach their hearts desire at last, and the White House will be adorned by a downright moron."
--H.L. Mencken, The Baltimore Evening Sun, July 26, 1920