When calling Any() on a null object, it throws an ArgumentNullException in C#. If the object is null, there definitely aren\'t \'any\', and it should probably return false.
The Any method runs against an IEnumerable and tells you whether there are any items in the Enumerable. If you don't give it anything to enumerate then an ArgumentNullException is reasonable: a collection with no (matching) elements is different to no collecion.