As Matt from Signal vs. Noise has pointed out, Tynt is the name of a copy-and-paste tracking web service that many of us have been using whether we like it or not. I, personally, like it!
If you’ve copy and pasted, or even just selected text or images from The New Yorker, SFGate, or TMZ (among a growing number of sites) you’re being tracked by Tynt. The easily installable code tallies the most selected text and images across your site to show which exact content your audience is “engaging” with, definitely an interesting metric.
Also, at the end of your paste is inserted the text: “Read more:” with a link back to the article. I’ve encountered this a few times, not knowing what exactly it was but it’s actually useful. If you don’t want the link back you can just delete the trailing text, however, the link directs specifically to the point in the article you selected and highlights it, giving whoever clicks through a strong point of reference.
There are so many ways that messing with ubiquitous interactions like copy-and-paste can backfire, but this is pretty successful in my opinion. However, I would definitely advocate for adding the “Read More:” link to be an opt-in, or at least opt-out rather than default setting. The tracking portion (which is what’s most interesting to me anyway) is simply the right of the website publisher.
Of course, the conspiracy theorists are already claiming to be “[selecting text] more often on this site just to push some noise into their profile.”