Add TechCrunch, Mashable, TheNextWeb, and PandoDaily to that list. I'm burned out and fatigued by the middlemen. Seriously, just link to the fucking content.
Clearly the plugin he's talking about is for people like you to hide these submissions from you - not in the hope that spammers will install it themselves and find themselves unable to submit.
Ah, I didn't think about it that way. Then you're back to Usenet killfiles; just hide the bad stuff (driving away newcomers who haven't learned to killfile yet) instead of getting rid of it.
i'd go for greasemonkey myself since that will work in chrome and firefox if done right. I think it can also work in safari, but i don't know about any others.