Im curious about how you'll implement that option. What i want to say is: I dont know what xattr's are, and i dont want to know what it is. I'm the user. Dont make me think. An option for it sound to me like a hotfix, but not a longterm solution. At some time i want to see my whole family and friends use this app. So when it leaves the beta-status it shoudlnt concern the user with such options. How about detecting OS's in the network to automate this option. Or somehow detecting conspicuous behavior in the sync-process of metadata-files. ...just some ideas.