Google has gone one step ahead amid the hue and cry of Panda updates about duplicate content that it would make the webmasters informed about the duplicate content with the help of Webmaster Tools messages, if Google detects any in your site and it is found pointing to some other URL as the source of content.

According to Google Webmaster Trends Analyst Pierre Far, if “cross-domain URL selection” has happened without any intention of yours, Google gives you an opportunity to improve the situation; otherwise they will simply downgrade the website. So, the ball is in your court now and only those people or websites are going to suffer who do not care about what Google says.

So, Google algorithms are all ready to detect duplication and infringement by other sites, the only difference now is that they will inform you about the URL which is using your content without permission. You can ask the particular party to remove that content, or else you can report it to Digital Millennium Copyright Act.