IANAL, but wouldn't websites like bash.org be prior art for a “click a button to vote up a story” functionality? I'd be interested to see the exact wording, if anyone can find a link to the patent in question.

Looks like it is this patent

http://www.patentgenius.com/patent/7831928.html

If that's the patent in question, it's so specific as to be useless.

The first claim, which all other claims depend on, only claims the invention when 1) The voting patterns are being displayed in a "swarm interface" 2) The "thickness of a line" is used for visualizing the number of votes

I don't believe that any of the modern sites use a swarm interface at all, and if someone wanted to show a swarm interface, by using something other than the thickness of a line for the visualization, you've sidestepped the patent.

It's hard to believe someone paid good money for this.

> It's hard to believe someone paid good money for this.

True, and the article mentions 15 patents, so the remaining is hidden somewhere in the USPTO database.

how much does that cost to file this kind of patent generally?