Here is a program that shuts them down before they get started. My thanks to jl scott for suggesting this tool. I didn't find anything of help to me, but I bookmarked the site and will check it now and them. You may want to do the same. Ezine AD Swap List - Offers a newsletter in which you can swap ads in your ezine for placement of yours in others.
Helps build reciprocal links.
It can also check on those who said they would link, but did not, or later took it down. I haven't tried it, but it sounds great. If you do, let me know how it goes. It's written by Will Bontrager, who is tops in my book. They represent Authorize.