What is the point of using a non-static local variable in a lock?

Question

A couple of times I have came across this code where a local variable in a class ( its NOT a static variable) has been used in a lock.

 public class SomeClass
{
    private object obj = new object();
    ....
    ....
    lock(obj)
    {

    }
}

Is there any point of locking given that its an instance variables?

Answer 1

Is there any point of locking given that its an instance variables?

Multiple threads could be acting on the same instance and a lock is needed for thread-safety. Think, for example, of a shared queue.