Method to compare two lists of the same type

ListCompare.cs

/// <summary>
/// Checks if two lists are equal
/// </summary>
/// <typeparam name="T">The type of the list</typeparam>
/// <param name="first">The first list</param>
/// <param name="second">The second list</param>
/// <returns>true when the lists are equal, otherwise false</returns>
public static bool ListsEqual<T>(IEnumerable<T> first, IEnumerable<T> second)
{
    if (first == null && second == null)
        return true;

    if (first == null)
        return false;

    if (second == null)
        return false;

    // Prepare the lists to avoid possible multiple enumerations
    var tmpFirst = first.ToList();
    var tmpSecond = second.ToList();

    // Step 1: Create a union list from the first and the second (only single entries. Duplicates will be removed automatically)
    var unionList = tmpFirst.Union(tmpSecond);

    // Step 2: Create a list with the entries, which are in both lists 
    var intersectList = tmpFirst.ToList().Intersect(tmpSecond);

    // Step 3: Get the entries which only in the union list and not in the intersect list
    var exceptList = unionList.Except(intersectList);

    // Final: If there are any entries in the except list, the lists are not equal
    return !exceptList.Any(); 
}