Figured I'd open an issue as I've been messing around this with gem today to try create something silly on Facebook, tried to post to a friends wall and got this error

Feed story publishing to other users is disabled for this application, x-fb-trace-id: EZaMJ3t2G8m [HTTP 403] (Koala::Facebook::ClientError)

apparently Facebook removed the ability for apps to post to walls via the Graph API in 2013