---- Pinterest Clears Up Copyright Fears With Site Opt-Out
DeeCee - 4:22 am on Mar 29, 2012 (gmt 0)
Pinterest images can be put up in two ways. Either users use Pinterest as the theft tool, in which case the Pinterest bot shows up. That is what the .htaccess code blocks. The second way is if users manually download your image and upload it to Pinterest, in which case blocking Pinterest will not help, if they do not know. The meta tag can block those too, but only if the user tells them that it was taken from that specific page on your site. If they merely use your image to show something else, the connection to you is unknown.
The code can be simplified a little. One of the lines is specific to Pfui doing some variable checking.
So assuming that they always come in with a user-agent containing the word Pinterest, it just does a fail condition on that