Earlier quoted context omitted.
How much more up-front than seeing your link go 'dead' could it be? After all it's not like anybody reads the guidelines linked above anyway before submitting a link, especially not if they're old hands (and most likely not even if they're not). Maybe a message could be added to the submission process that said: "You've used a URL shortener, bang , you're dead", but that's pretty obviously the reason why. After all,…
The URL shortener was just an example -- just one example. My point is not about bit.ly or anything like it. My point is: there are apparently a bunch of rules, and I don't have the sense that I understand them. Worse, I have the sense that asking about the rules is frowned upon. I find this a little chilling, and it seems to fly in the face of the quasi-libertarian spirit I generally find on HN.
Right now, there are spammers repeatedly submitting shortened URLs to their WOW Gold sites and not checking to see if they're killed. That actually stops a good fraction of it, because frankly, they're not very smart people.
If you told them exactly why their current tactic is not working, they'd immediately move on to the next one and the next one until they find one that works.