[Hexstream]

Seems to me this kind of behavior grossly encourages linkbait.

edit: In fact I'd be all for preventing voting on links before following them. A nice, clean way to do it would be a bit of unobstrusive Javascript+cookies to track which stories you've been to and hide the upvote link if you haven't seen the story yet.

It's not secure but it doesn't have to. Implementing it this way has the advantage of not having any bigger load on the server and still being able to follow links to stories without contacting the HN server.