title: SecurityAction.RequestMinimum is obsolete in .Net 4.0
body: <p>Recently, our .Net client libaray is upgrading to compile against Net 4.0.
  After change the target framework to 4.0, the application has some compilation error.</p>
  
  <p>In <code>AssemblyInfo.cs</code>:</p>
  
  <p><code>[assembly: SecurityPermission(SecurityAction.RequestMinimum, Execution = true)]</code></p>
  
  <blockquote>
    <p>Error  7   Warning as Error: 'System.Security.Permissions.SecurityAction.RequestMinimum' is obsolete: '"Assembly level declarative security is obsolete and is no longer enforced by the CLR by default. See <a href="http://go.microsoft.com/fwlink/?LinkID=155570" rel="noreferrer">http://go.microsoft.com/fwlink/?LinkID=155570</a> for more information."'
    `</p>
  </blockquote>
  
  <p>In .Net 4.0, it shows that: <code>SecurityAction.RequestMinimum</code> as obsolete, and we treat all warning as error.</p>
  
  <p>What I should do with it? - Just remove it(will this has some unexpected impact? for example when the dlls are used in IIS) or change to some other value?
  I am not familiar with .Net, especially its security mechanism.</p>
  
  <p>Anyone can help on this? Thanks for any advice and comment :)</p>