It's even harder to get away with pirating fonts now with web fonts. Either the service can detect you pulling a font for a domain that isn't paying for it or webcrawlers will find unpaid fonts.
Is that really a thing? Markup in a web page tells how to display the text. Saying "use this font over here on this other server" seems fair game on some level. Might not be on another level, but it's technically the end user downloading a file that's publicly available on some server.