PowerShell: Update target Audience of a SharePoint 2010 Web Part

 # Get reference to the SPSite object  
 $SPWeb = Get-SPWeb "http://sharepoint"  
 # Get reference to the landing page. Since it is a publishing site so default.aspx is the landing page   
 $page = $SPWeb.GetFile("Pages/index.aspx")   
 ### Uncomment the lines below to perform the update  
 #$page.CheckOut()   
 # //Get reference to the webpartmanager class   
 $webpartmanager = $SPWeb.GetLimitedWebPartManager("Pages/index.aspx", [System.Web.UI.WebControls.WebParts.PersonalizationScope]::Shared)    
 # Double check the web part that you wish to update. Iterate through webparts in webpartmanager class   
 for ($i=0;$i -lt $webpartmanager.WebParts.Count;$i++)   
 {    
      #write-host $webpartmanager.WebParts[$i].title  
      # Check for the name of required web part    
      if($webpartmanager.WebParts[$i].title -eq "Content Query Web Part")    
      {    
           #Get reference to the web part   
           $wp = $webpartmanager.WebParts[$i];   
           write-host $wp.title " " $i  
           # If there is any existing filter, copy it  
           write-host $wp.AuthorizationFilter  
           # In the filter (empty: ;;;;;;), first two semicolons: individual users as target audience; second two semicolons: distribution list; last two semicolons: can be replaced to include sharepoint groups    
           # e.g. "174e7e9d-ff39-4856-85a6-9247b02e59fb,124f1234-3998-4b54-83d1-abc4048fb9b4;;;;"  
           ### Optionally perform direct update while in for loop  
           # Other properties e.g. chrome property   
           #$wp.ChromeType="TitleAndBorder";   
           # Save changes to webpartmanager. This step is necessary. Otherwise changes wont be reflected   
           #$webpartmanager.SaveChanges($wp);   
  }    
  }    
 ### Uncomment the lines below to perform the update  
 #$wp = $webpartmanager.WebParts[26];  
 #write-host "begin update: " $wp.Title  
 #$wp.AuthorizationFilter = "174e7e9d-ff39-4856-85a6-9247b02e59fb,124f1234-3998-4b54-83d1-abc4048fb9b4,3a87dc31-9067-4996-b4c2-5efc6ff3eab7,68d2a840-bdbb-44ee-aacd-395b5551c473,7add71c2-dbea-4218-b8ff-f6b112f225e4,577550be-616e-41cd-90a4-493c030ddd72,9f113155-7c70-4d18-9417-851d82ba8b6a,c664006b-ec7f-4798-9acc-c48766be68a8,e26f7ece-615c-474d-9db9-0f60953e113a,ee912564-4f77-43c4-aced-55d387bc4e8e,51d2b9df-7ca3-42ad-a307-f9fdf28fe417,59500291-5912-47c0-b6a2-9c9adf24f2da;;;;";  
 #$webpartmanager.SaveChanges($wp);  
 #write-host "saving webpart target audience done...";  
 ### Uncomment the lines below to check in and Publish the page   
 #$page.CheckIn("Update Audience(batch powershell)")   
 #$page.Publish("Update Audience batch powershell)")   
 #$SPWeb.Update();    
 # Dispose SPWeb object   
 $SPWeb.Dispose();