Van ennek értelme?

using System;
using System.Security.Permissions;
using System.Windows.Forms;

namespace foo
{
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.PropertyGrid propertyGrid1;

public Form1()
{
this.propertyGrid1 = new System.Windows.Forms.PropertyGrid();
this.SuspendLayout();
this.propertyGrid1.Dock = System.Windows.Forms.DockStyle.Fill;
this.propertyGrid1.SelectedObject = this.propertyGrid1;
this.ClientSize = new System.Drawing.Size(292, 273);
this.Controls.Add(this.propertyGrid1);
this.ResumeLayout(false);
}

[STAThread]
[FileIOPermission(SecurityAction.Deny, Read = "C:\\temp\\xxx.txt")]
static void Main()
{
Application.Run(new Form1());
}
}
}