This is an ingenious – and completely free – program designed to be installed on a Web server. It will sabotage the automatic 'bots sent out by spammers to collect email addresses from Web sites, and it will pollute their email address database with thousands of fake email addresses. The creator of the program explains it like this: "The idea behind wpoison is really very simple. Junk E-Mailers write programs to automatically scan thousands and thousands of web pages, looking for E-Mail addresses which they then send unsolicited junk E-Mail to (or which they sell to other spammers). By and large, these address harvesting web crawlers are about as intelligent as the spammers who use them and/or develop them, which is to say not very. These programs can be easily fooled into accepting lots and lots of completely fake and useless E-Mail addresses, so long as the bogus addresses in question appear to reside on ordinary nondescript web pages. That is where wpoison comes in."
I've successfully installed wpoison myself, so you can see it in action yourself. Just go here:
Notice that the actual executable file has been renamed to "customers" so as to attract more spammer bots.