"Sorry For You" = SFY used as a brief acronym to show you feel for someone in chat conversations. Gernally said in a sarcastic way denoting you are glad you aren't them because you would feel really bad if it was happening to you, but probablly don't give a shit and think it's funny because it's not happening to you.
Statement: I'm hella sick atm. I've got stuffy, sneezy, coughy, achy...and I don't like Nyquil.
Reply: Hahahaha your sick SFY!
Statement: My mom is going to college.
Reply: Hahaha, wow SFY
Statement: I am leaving work early, SFY.