best action to take when banning bots?

I'm trying to decide what status and response to make

[nonprof webguy]

I'd like to seek some advice from others who work with ASP on this one:

I'm adding a script to the Session_OnStart section of my global.asa file that will do two things:

1. ban particular robots
   
2. refuse to answer request for bad files
   

Identifying which robots and which file requests I want to ban is the easy part. For example, I'm banning a number of e-mail harvesters, and I'm also banning requests for URL stems such as the following:

• /_vti_bin/owssvr.dll
  
• /_vti_bin/..%5c../..%5c../..%5c../winnt/system32/cmd.exe
  

My question is what to program my script to do when it encounters a banned robot or URL request. The options I'm considering include

• redirecting to a blank html file
  
• simply issuing response.end
  
• sending a status code and response.end
  
• sending a status code and some other response action
  

Can anyone suggest what action will use the least server resources, or what advantages particular responses or status codes might have? For banned bots, is there a status I could send that would discourage them from returning?

Any thoughts or insight on these questions is appreciated. It's been a while since I've posted on WebmasterWorld, and it's good to be back!

[wardbekker]

Feed the Bot some e-mail adresses used for reporting spam otherwise just send a 404 or 400. Or maybe a redirect to the bots ip-adress?