Some kind of flow history: http://www.quora.com/What-do-the-strange-characters-in-Linke...

Since it is for internal use, I doubt you'll get a more detailed explanation.

I recall its to prevent XSS attacks.

I'd be most interested if someone can explain clearly what part it plays, though.

Maybe someone was slightly too clever, too clever by half, or not clever at all.

this is not only on Linkedin, I have seen other url like this. Too interested in the answer.