Facebookmancy 

The practice of predicting the future (e.g relationships) by studying facebook profiles.

I was doing a bit of facebookmancing and I reckon John and Liz are gonna get together at Dave's party next week.

"Did you hear that John and Liz are together?"
"Wow! Craig facebookmanced that ages ago!"

Craig's got into facebookmancy recently, and it turns out he's scarily accurate

Facebookmancy by Simon Canwell June 13, 2008

Facebookacy 

A disease created from being on facebook too much, originated in Norway

Stephanie had facebookacy from talking on facebook too much.

Facebookacy by G-man J July 27, 2010