Griefing, yes. The audience for our mobile app skews young and, shall we say, less "serious aviators" than the desktop sim, so to some degree people like that you can buzz a 747 on short final in an F-22. :D

Long-term we've talked about things like a reputation system, where flying responsibly would earn you points to get into a separate "world" filled with people who also want to do more serious flying.