In visual noise on blogs, Andreas argues against the excessive use of XML buttons and favicons on blogs and websites.Social Bookmark Icons: People using social bookmarking services such as Digg, del.icio.us or Furl usually know how to add items to their accounts and don't need your favicons.
XML Buttons: Potential subscribers will probably use their feed reader's "subscribe to" bookmarklet, a plugin or their reader's interface and don't need all those links to third-party services.
I like his reasons though I may not immediately follow them. What is your opinion ?