Ask HN: Why don't you ban the dead link forever?

Hey,<p>I notice that dead links can be submitted over and over again!<p>For example, someone out there keeps sending the Google mozzila homepage. Like here: http://news.ycombinator.com/item?id=505915<p>If an entry is submitted as dead, do you block the link forever, or you just allow it to be submitted over and over again, and abuse us?<p>Thanks!<p>EDIT: If someone submits a link, and you mark it as dead because it's spam, then why don't you make a technique that in case another user submits the same link again, the entry becomes dead automatically?<p>Also why don't you monitor a "high risk users" with many spam entries? Such users are more likely to be posting spam, so monitoring them - maybe automatically - you will reduce the spam flow here.<p>Also consider users with no history record as a potential spammers.<p>Thanks.