Rogers Cadenhead: If you're going to point a dead site's feed to nowhere, why not simply delete it? Any decent aggregator will eventually dump a feed that results in "file not found" errors
If your server supports it, a 410 status code means gone. Whereas a 404 status code may be transient, a 410 is clearly intentional, so you would think that any decent aggregator would respect a 410, wouldn't you?
Well, last year, I created a feed for Esther Dyson's Release 4.0. She since has moved to another server and produces a mostly valid RSS 2.0 feed (the problem is the 27 differences between iso-8859-1 and windows-1252).
I've long since removed my scraped feed, and marked it gone.
Despite this, a number of aggregators continue to relentlessly poll for changes.
Stop that. Please.