Yes, in LittleBigPlanet, according to the latest issue of GameInformer, users will only be allowed to upload 3 levels to the LittleBigPlanet servers and if you make exceptional levels, that limit will more than likely be upped.
Also, your friends can play as many levels as you create, even the ones with questionable content.
Oh, and if you want to report someone’s level, there couldn’t be an easier way than by pressing the Good Grief button (Select).
You can only upload 3 levels online! Too many limitations? [PS Forums]