Quite recently, I was trying out a few new plugins which came across as interesting to me. As usual, I ran up my test install and installed the plugins, everything worked fine, except for one thing. Couple of plugins from the lot added linkbacks to their own site, that is fine, however, they did not

More at: http://weblogtoolscollection.com/archives/2010/02/13/forced-links-added-by-plugins/