A good companion to all your digging activities is DiggStatistics. It’s not a productivity tool, but it does a good job at keeping the place clean.
The deadbeats list is a great feature as it tells you who doesn’t reciprocate your invitations, that it be friendship or calls to action.
Just browse through the list and get rid of the useless contacts in there. On Digg, browsing through your list of friends is hell, so you almost never go through the process of cleaning your Digg rollodex. But from Diggstatistics, it’s sorted out for you. Just click on and unfriend the unwanted.
And sometimes you land on this page. For example, Zaibatsu’s page gives one of those error page (Get my point?). Since I can’t access their profile pages, I cannot click the unfriend link. And since managing friends on Digg.com is hell, I will simply remain a fan of those banned users for ever…
… And so will the 4275 fans of Diggboss, the 6508 fans of Supernova17, or the 9297 fans of Zaibatsu. Chop off a top digger’s head, its body will haunt your domain forever!