In R0, the user who owns China Eastern also owns Swiss International Air Lines.
I noticed that China Eastern consistently had more planes than other airlines, even though they had only started delivery a year or so prior.
A little bit of digging reveals a pattern of Swiss International purchasing and then immediately selling aircraft, which are purchased by China Eastern. I am unable to find a single Swiss International aircraft that was purchased by anyone else, so this is clearly deliberate and the user is keeping track of when Swiss International sells their planes so they can be purchased on the exact day they come on the used market.
Pretty scummy, if you ask me. Only one airline should be allowed per user, per world.