Can C# extension methods access private variables?

Question

Is it possible to access an object\'s private variables using an extension method?

Answer 1

No:

public class Foo
{
    private string bar;
}

public static class FooExtensions
{
    public static void Test(this Foo foo)
    {
        // Compile error here: Foo.bar is inaccessible due to its protection level  
        var bar = foo.bar;
    }
}