Best blogging tip I've seen in years, as I find this bit of nonsense remarkably annoying (if you blog, you'll recognize this immediately). And I always link to source:

Tynt, the Copy/Paste Jerks
Over the last few months I've noticed an annoying trend on various web sites, generally major newspaper and magazine sites, but also certain weblogs. What happens is that when you select text from these web pages, the site uses JavaScript to report what you've copied to an analytics server and append an attribution URL to the text. So, for example, if I were using this "service" here on Daring Fireball, and you selected the first sentence of this article, copied it, then switched to another app to paste the text you just copied, instead of pasting just the sentence you selected and intended to copy, you'd instead get:

"...Over the last few months I've noticed an annoying trend on various web sites, generally major newspaper and magazine sites, but also certain weblogs.

Read more: http://daringfireball.net/2010/05/tynt_copy_paste_jerks/#ixzz0oyLiD4Qh..."

I.e., three blank lines followed by "Read more:", then the URL from which the text was copied, then an identifying hash code used for tracking purposes...

...All of this nonsense - the attribution appended to copied text, the inline search results popovers - is from a company named Tynt, which bills itself as "The copy/paste company".

It's a bunch of user-hostile SEO bullshit.

Everyone knows how copy and paste works. You select text. You copy. When you paste, what you get is exactly what you selected. The core product of the "copy/paste company" is a service that breaks copy and paste...

HOW TO BLOCK TYNT ON A PC OR MAC

...Here's the line I added to the end of my /etc/hosts file:

127.0.0.1 tcr.tynt.com

After saving the hosts file, Tynt's clipboard-altering nonsense is disabled on all Tynt-using websites I've encountered, no matter which browser I use...

Source: Daring Fireball

...that change in your /etc/hosts file breaks Tynt's entire business model, the assholes...