How do I restrict the content of stack trace to Client of Web Service in ASP.Net

Here I have created sample that will help you out.

I have make use of custom Attribute

FewService(WebService)

[WebMethod]
// Use Parameterized GlobalErrorHandler to Specify Error Discription.
[GlobalServiceErrorHandler("Divide operation Mathmatical Error")]
public double Divide(int numerator, int denominator)
{
    try
    {
        return numerator / denominator;
    }
    catch (Exception e)
    {
        throw new GlobalErrorHandler(e).faultException;
    }
}

[WebMethod]
// Parameterless GlobalErrorHandler throws General Error Discription.
[GlobalServiceErrorHandler]
public byte[] GetFileContent(string path)
{
    try
    {
        return File.ReadAllBytes(path);
    }
    catch (Exception e)
    {
        throw new GlobalErrorHandler(e).faultException;
    }
}

GlobalServiceErrorHandlerAttribute(Class)

public class GlobalServiceErrorHandlerAttribute : Attribute
{
    public GlobalServiceErrorHandlerAttribute()
    {
        this.Description = "General Exception";
    }
    public GlobalServiceErrorHandlerAttribute(string description)
    {
        this.Description = description;
    }
    public string Description { get; set; }
}

GlobalErrorHandler

public class GlobalErrorHandler
{
    public readonly FaultException faultException;

    /// <summary>
    /// 
    /// </summary>
    /// <param name="e"></param>
    public GlobalErrorHandler(Exception e)
    {
        this.faultException = GetFaultedException(e);
    }

    /// <summary>
    /// Frame the detail message from exception
    /// </summary>
    /// <param name="ex"></param>
    /// <returns></returns>
    public static FaultException GetFaultedException(Exception ex)
    {
        if (ex is FaultException)
            return ex as FaultException;

        StringBuilder messageBuilder = new StringBuilder();
        Type attributeType = typeof(GlobalServiceErrorHandlerAttribute);
        int step = 1;

        var attributes = GetStackTraceSteps<GlobalServiceErrorHandlerAttribute>(ex);
        if (attributes != null && attributes.Count > 0)
            messageBuilder.AppendLine(string.Format
            ("Sorry there is a problem while processing step {0}:", attributes.Count));
        foreach (var attribute in attributes)
        {
            messageBuilder.Append(string.Format
            ("Step {0}: {1}", step.ToString(), attribute.Description));
            messageBuilder.AppendLine();
            step++;
        }
        messageBuilder.AppendLine();

        string formatedMessage = string.Format("{0}", messageBuilder.ToString());
        return new FaultException(formatedMessage);
    }

    /// <summary>
    /// Extrace the custom attribute details from the stacktrace
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="ex"></param>
    /// <returns></returns>
    public static List<T> GetStackTraceSteps<T>(Exception ex)
    {
        List<T> traceSteps = new List<T>();
        Type attributeType = typeof(T);
        StackTrace st = new StackTrace(ex);
        if (st != null && st.FrameCount > 0)
        {

            for (int index = st.FrameCount - 1; index >= 0; index--)
            {
                var attribute = st.GetFrame(index).
                GetMethod().GetCustomAttributes(attributeType, false).FirstOrDefault();
                if (attribute != null)
                {
                    traceSteps.Add((T)attribute);
                }
            }
        }
        return traceSteps;
    }
}

Default.aspx(Dividision Calculation)

<div>
    <table border="0" cellpadding="0" cellspacing="0">
        <tr>
            <td>
                Numerator:
            </td>
            <td>
                <asp:TextBox ID="txtNumerator" runat="server" />
            </td>
        </tr>
        <tr>
            <td>
                Denominator:
            </td>
            <td>
                <asp:TextBox ID="txtDenominator" runat="server" />
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <asp:Button Text="Divide" runat="server" OnClick="Divide" />
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <asp:Label ID="lblResult" runat="server" />
            </td>
        </tr>
    </table>
</div>

 C#

protected void Divide(object sender, EventArgs e)
{
    FewService.FewServiceSoapClient client = new FewService.FewServiceSoapClient();
    lblResult.Text = client.Divide(Convert.ToInt32(txtNumerator.Text), Convert.ToInt32(txtDenominator.Text)).ToString();
}

ReadFile.aspx(Read File Content)

<div>
    Enter FilePath:<asp:TextBox ID="txtFilePath" runat="server" />
    <asp:Button Text="Read" runat="server" OnClick="ReadFileContent" />
</div>

C#

protected void ReadFileContent(object sender, EventArgs e)
{
    if (!string.IsNullOrEmpty(txtFilePath.Text))
    {
        FewService.FewServiceSoapClient client = new FewService.FewServiceSoapClient();
        client.GetFileContent(txtFilePath.Text);
    }
}

Screenshot