FTP Snatching -- In response to our FAQtoid that mentioned how spammers might capture your email address when you visit a Web page, Peter N Lewis <peter@stairways.com.au> noted a sneaky technique involving FTP:

Another way I've heard to snatch an email address when visiting a Web page is by coding an inline image with an FTP URL. The browser then automatically FTPs the file for you to show you the image - but when it anonymously FTPs the file, the browser typically uses your email address as the password (as anonymous FTP should - sending your email address is taken as a signature to abide by the usage guidelines). Thus an unscrupulous FTP server (or Web server using the anonymous FTP inline image) can capture your email address as well.