There is an interesting combination between public and private blockchain networks and that is the sol called semi-public network. In such a field, the network will be operated or governed by several semi-trusted actors, but the network itself from a development or application point of view is open for everybody. However, it is pretty much questionable if that model can work at all. The model is that an application or transaction can only be censored if a majority of the consortium members will vote for that. It is good question what is going to happen on the practical side if an application is not conform with a regulation of a certain region. One model is that an application can only be filtered if most of the regions vote the application out. Exactly the opposite can happen however from the practical side as well, there might be the situation where an application has to be conform not just with one regulation of a certain region but with all regulation of all of the regions.
