is it a bug? protection attributes on interfaces/abstracts have no effect outside module?

[dennis luehring]

repost from d.learn

is it a bug? protection attributes on interfaces/abstracts have no 
effect outside modules?

module types;

private interface itest
{
    public void blub2();
    private void blub3();
}

private class test
{
    protected abstract void blub4();
    public abstract void blub5();
}

---

module classes;

import types;

class A: itest
{
    public void blub2(){}
    public void blub3(){}
}

class B: test
{
    protected override void blub4(){}
    public override void blub5(){}
}

class C: test
{
    public override void blub4(){}
    public override void blub5(){}
}

should the attributes do anything or is it a bug to allow the usage?