I found this solution:

Download DDK (Disturbance Developer Kit) from:

http://www.thing.net/~rdom/ecd/floodnet.html


Unzip the file. Then edit the file applet.htm (with a text editor). Change the target URL to the desired url of the spam advertisement (it is set now on www.whitehouse.gov). Then doubleclick on zaps.htm (or on index.htm and then on the link ''begin flooding''). Don't doubleclick on applet.htm, because then each automatic reload will open in a new window.