What does the 'friend' modifier do in VB.NET?
Why is it the default modifier for GUI components in Visual Studio?
friend
in VB.Net is the same as internal
in C#, it means that it can be accessed anywhere in the same assembly, but not from other assemblies.
I think it's a sensible default since I would say that normally one assembly should not be using another assembly's GUI controls (unless it's a class library or similar that is built for the purpose).